Optical modulating/display device and production method therefor and display apparatus mounting the optical modulating/displaying device thereon

ABSTRACT

The present invention relates to an optical modulating display device ( 200 ) such as a liquid crystal displaying device provided with a front-light type planar illuminating device.  
     The above front-light type planar illuminating device allows illuminating light to propagate inside a substrate ( 1 ), and is provided with a low refraction layer ( 3 ) being lower in refractive index than the substrate ( 1 ) and being in close contact with the inner surface of the substrate ( 1 ), and with reflection structure ( 11 ) on the outer surface of the substrate ( 1 ).  
     The optical modulating display device ( 200 ) provided with the above front-light type planar illuminating device can ensure a sufficient amount of guide light propagating inside the substrate ( 1 ) and reduce non-uniformity in display illumination.  
     And a display apparatus mounting the above optical modulating display device ( 200 ) thereon can be reduced in thickness and weight and provide a high quality display.

TECHNICAL FIELD

The present invention relates to an optical modulating display deviceprovided with a planar illuminating system for illuminating a displayingdevice, a production method therefor and a display apparatus mountingthe optical modulating display device thereon.

BACKGROUND OF THE ART

A reflective liquid crystal displaying device is widely used for adisplay of an electronic apparatus such as a cellular phone and apersonal digital assistant of which a main power supply is a battery.The reflective liquid crystal displaying device, however, uses anambient external light, therefore when ambient light is poor like innight time, display is not easy to be seen or cannot be seen.Consequently, in these years, the reflective liquid crystal displayingdevice is provided with a front light for illuminating from anobserver's side, whereby the front light is put the light on in order tomake it easy to see the display even in an environment such as in thedark where the ambient light is poor. A technique is known which usesthe ambient light for normal display and which illuminates from a rearof a semi-transparent liquid crystal displaying device in the case ofpoor ambient light thereby making it easy to see the display.

Also, an electronic paper has been developed as a display medium takenover from paper. The electronic papers using a cholesteric liquidcrystal or taking advantage of electrophoretic migration have beendeveloped.

However, if a liquid crystal displaying device is provided with a frontlight on the outside thereof, a depth feel corresponding to thickness ofthe front light occurs on a display, thereby resulting in deteriorationin quality level of display. As a solution for this problem, a structureis known in which optical guiding function of the front light is givento a transparent substrate at an observer's side of the liquid crystaldisplaying device. A typical example of this structure is disclosed in,for instance, Japanese Laid-Open Patent Publication No.2001-215509(first prior art). FIG. 1 is a cross-sectional view illustrating aconstitution of a liquid crystal displaying device in the first priorart.

A conventional liquid crystal device includes a laminated structurecomprising an observer's side polarizer 35a, an observer's sidetransparent substrate 31, a transparent electrode 32, a liquid crystallayer 36, a transparent electrode 33, a rear transparent substrate 34, arear polarizer 35b, and a reflective layer 37 and a light source 38extending along a side portion of the observer's side transparentsubstrate 31. In the first prior art, microscopic concavity andconvexity are formed on an observer's side surface of the observer'sside transparent substrate 31, whereby the optical guiding function ofthe front light is given to the observer's side transparent substrate31. Such a structure eliminates thickness of the front light, therebyallowing the above-described problem of deterioration in quality levelof display to be overcome.

In the first prior art, however, the transparent electrode 32 is indirect contact with a lower part of the observer's side transparentsubstrate 31. The transparent electrode used in the liquid crystaldisplaying device is normally composed of ITO (Indium Tin Oxide). Arefractive index of the transparent electrode composed of ITO depends onits film forming method, however generally the refractive index isapproximately 1.7 to 2.0. Specifically, in the case of forming a filmthrough a vapor deposition technique, the refractive index isapproximately 1.7. In the case of forming the film through an ionplating technique, the refractive index is approximately 1.8 to 1.9. Inthe case of forming the film through a sputtering technique, therefractive index is approximately 1.9 to 2.0. Namely, in the case offorming the film of the transparent electrode through any film formingtechniques, the refractive index (approximately 1.7 to 2.0) of thetransparent electrode is higher than the refractive index (about n=1.5)of the transparent substrate. Light entering from a side face of thetransparent substrate, therefore, does not cause total reflection on aboundary surface between the transparent substrate and the transparentelectrode, almost all of the incoming light outgoes to a liquid crystallayer 8 in the vicinity of the side face of a light incoming side. Thus,light guiding may not be sufficiently performed up to an opposite sideface to the light incoming side which is a side face opposite to theside face of the transparent substrate into which the light enters.Almost all of the incoming light also concentrates in the vicinity ofthe light incoming side. Thus, display is bright at a position near thelight incoming side, however the display gets darker as receding fromthe light incoming side, that is to say, as approaching the other lightincoming side. Consequently, non-uniformity in display illumination iscaused in a display surface.

A second prior art is disclosed in Japanese Laid-Open Patent PublicationNo.2001-21883 (second prior art). In the second prior art, a polarizer,a retarder, a diffuser, a color filter, and a transparent electrode arearranged on the lower side of first substrate (a glass substrate) havingconcavity and convexity which function as a light guiding plate of afront light. Similar to the first prior art, however, refractive indexof PVA (polyvinyl alcohol) which is generally used as a main componentof the polarizer is 1.49 to 1.53, which is the same level as, or largerthan, the refractive index of the glass substrate, therefore the lightentering into the substrate may not perform sufficient light guiding upto the opposite side face to the light incoming side.

An electronic paper has been further developed in various methods,however, a type such as the above reflective liquid crystal displayingdevice which has an external light source is not generally known, in thecase of poor ambient light such as in the night time, display on theelectronic paper is not easy to be seen or cannot be seen. Theelectronic paper is provided with the front light in the first prior artor the second prior art to allow the problems arising in the case of thepoor ambient light to be overcome, however the other problems caused byproviding with the front light cannot be solved.

DISCLOSURE OF THE INVENTION

An object of the present invention is to provide an optical modulatingdisplay device allowing problems and defects associated with the priorarts to be solved.

Further object of the present invention is to provide an opticalmodulating display device which ensures an amount of guide light forperforming sufficient light guiding of an incoming light up to anopposite side face to light incoming side and which achieves reductionof non-uniformity in display illumination in the optical modulatingdisplay device given a light guiding function to a substrate sandwichingan optical modulating layer.

Further object of the present invention is to provide a productionmethod for an optical modulating display device allowing problems anddefects associated with the above prior arts to be solved.

Further object of the present invention is to provide a productionmethod for an optical modulating display device which ensuring an amountof guide light for performing sufficient light guiding an incoming lightup to an opposite side face to light incoming side and which achievesreduction of non-uniformity in display illumination in the opticalmodulating display device given a light guiding function to a substratesandwiching an optical modulating layer.

Further object of the present invention is to provide a liquid crystaldisplaying device allowing problems and defects associated with theabove prior arts to be solved.

Further object of the present invention is to provide a productionmethod for a liquid crystal displaying device which ensures an amount ofguide light for performing sufficient light guiding of an incoming lightup to an opposite side face to light incoming side and which achievesreduction of non-uniformity in display illumination in the opticalmodulating display device given a light guiding function to a substratesandwiching an optical modulating layer.

First embodiment of the present invention provides an optical modulatingdisplay device, including a multilayer structure containing an opticalmodulating layer and a pair of first and second substrates sandwichingthe multilayer structure, wherein

-   -   at least the first substrate is constituted so that light        propagates therein,    -   the multilayer structure is constituted so that a boundary        surface between the first substrate and the low refraction layer        causes total reflection of the light incoming into the boundary        surface in an oblique direction by including a low refraction        layer being lower in refractive index than the first substrate        and being in direct contact with the first substrate.

Preferably, a refractive index (nL) of the low refraction layer and arefractive index (nl) of the first substrate meet conditions given bynL−nl<−0.01.

The optical modulating layer may be constituted of a liquid crystallayer.

The optical modulating display device further includes a reflectionstructure for reflecting at an angle perpendicular to, or nearlyperpendicular to, the boundary surface at least a part of the lightincoming in an oblique direction from the first substrate at an oppositeside to the low refraction layer with reference to the first substrate.

The reflection structure comprises a layered structure having at leasteither of a plurality of protrusions or a plurality of grooves at anopposite side to the first substrate.

At least either of the plurality of the protrusions or the plurality ofthe grooves preferably exist in almost the same region as a displayingregion of the optical modulating display device.

The low refraction layer may be composed of a transparent material.

The low refraction layer may be composed of SiO₂ or MgF.

The optical modulating layer comprises a liquid crystal layer and themultilayer structure may be constituted so as to further include apolarizing layer, where only specific polarized light transmits, betweenthe low refraction layer and the liquid crystal layer.

The optical modulating layer comprises a liquid crystal layer, themultilayer structure may be constituted so as to further include aplurality of color polarizing layer transmitting only specific polarizedlight of different specific wavelength band and being spatially arrangedwithin each pixel region between the low refraction layer and the liquidcrystal layer.

The optical modulating layer comprises a liquid crystal layer and themultilayer structure may be constituted so as to include a polarizinglayer transmitting only specific polarized light and at least one ormore phase difference layer between the low refraction layer and theliquid crystal layer.

The optical modulating layer comprises a liquid crystal layer, themultilayer structure may be constituted so as to include a plurality ofcolor polarizing layer transmitting only specific polarized light ofdifferent specific wavelength band and being spatially arranged withineach pixel region, and at least one or more phase difference layerbetween the low refraction layer and the liquid crystal layer.

The optical modulating layer comprises a liquid crystal layer and themultilayer structure may be constituted so as to include a laminatedbody laminated with a color filter layer transmitting light of differentspecific wavelength band, a polarizing layer transmitting only specificpolarized light, and at least one or more phase difference layer in thisorder between the low refraction layer and the liquid crystal layer.

Preferably, a light source is arranged in the vicinity of first side endof the first substrate and the first side end is protruded outsidecompared with a side end of second substrate.

The optical modulating layer comprises a liquid layer and the multilayerstructure may be constituted so as to further include a seal memberprovided in a peripheral region of the liquid crystal layer included inthe multilayer structure and a light blocking layer adjusted so as tooverlap the seal member viewed from a direction perpendicular to theboundary surface in order to attach the pair of first and secondsubstrates.

The optical modulating layer comprises a liquid crystal layer and themultilayer structure may be constituted so as to further include a sealmember provided for attaching the pair of the first and secondsubstrates in a peripheral region of a laminated body in which a colorfilter layer transmitting light of different specific wavelength band, apolarizing layer transmitting only specific polarized light, and atleast one or more phase difference layer are laminated in this orderbetween the low refraction layer and the liquid crystal layer.

The optical modulating layer comprises a liquid crystal layer and alight source is provided in the vicinity of the first side end of thefirst substrate, a liquid crystal inlet used when injecting a liquidcrystal material between the pair of the first and second substrates isprovided at a side of the liquid crystal layer different from the firstside end.

Second embodiment of the present invention provides an opticalmodulating display device including a multilayer structure containing anoptical modulating layer and an optical propagating region constitutedso that refractive index is uniform and that light propagates therein,wherein the multilayer structure is constituted so that a boundarysurface between the optical propagating region and the low refractionlayer causes total reflection of the light incoming into the boundarysurface in an oblique direction by including a low refraction layerbeing lower in refractive index than the optical propagating region andbeing in direct contact with the optical propagating region.

A refractive index (nL) of the low refraction layer and a refractiveindex (nl) of the optical propagating region preferably meet a conditiongiven by nL−nl<0.01.

A reflection structure is preferably further included, wherein at leasta part of light incoming in an oblique direction from the opticalpropagating region is reflected at an angle perpendicular to, or nearlyperpendicular to, the boundary surface at an opposite side to the lowrefraction layer with reference to the optical propagating region.

The reflection structure may be constituted of a layered structurehaving at least either of a plurality of protrusions or a plurality ofgrooves at an opposite side of the first substrate.

The low refraction layer may be constituted of a transparent material.

The optical propagating region may comprise a substrate constituted sothat light propagates therein. The optical propagating region may beconstituted so as to include the substrate constituted so that the lightpropagates therein, and a thin film inserted between the substrate andthe low refraction layer and being the same in refractive index as thesubstrate. The substrate, for instance, corresponds to the firstsubstrate in other embodiments of the present invention.

Third embodiment of the present invention provides a liquid crystaldisplaying device including at least: first and the second substratesforming a pair, wherein at least the first substrate is constituted sothat light propagates therein; a light source provided in the vicinityof the first side end of the first substrate; a multilayer structuresandwiched between the first and second substrates, including a lowrefraction layer being lower in refractive index than the firstsubstrate and further being in direct contact with the first substrate,a color filter layer transmitting light of different specific wavelengthband, a polarizing layer transmitting only specific polarized light, andat least one or more phase difference layer; a reflection structure forreflecting at an angle perpendicular to, or nearly perpendicular to, theboundary surface at least a part of light incoming in an obliquedirection from the first substrate at an opposite side to the lowrefraction layer with reference to the first layer: wherein a boundarysurface between the first substrate and the low refraction layer causestotal reflection of the light incoming into the boundary surface in anoblique direction.

A refractive index (nL) of the low refraction layer and a refractiveindex (nl) of the first substrate preferably meet a condition given bynL−nl<−0.01.

The reflection structure may be constituted a layered structure havingat least either of a plurality of protrusions or a plurality of groovesat an opposite side to the first substrate.

At least either of a plurality of the protrusions or a plurality of thegrooves preferably exists in the nearly same region as a displayingregion of the optical modulating display device.

The low refraction layer may be composed of a transparent material.

The low refraction layer may be composed of SiO₂ or MgF.

The first side end of the first substrate is preferably protrudedoutside compared with a side end of the second substrate.

The multilayer structure may be constituted so as to further include aseal member provided for attaching the pair of the first and secondsubstrates in a peripheral region of a liquid crystal layer included inthe multilayer structure and a light blocking layer adjusted so as tooverlap the seal member viewed from a direction perpendicular to theboundary surface.

The multilayer structure may be constituted so as to further include aseal member provided for attaching the pair of first and secondsubstrates in a peripheral region of the color filter layer, thepolarizing layer, and the phase difference layer as well as the liquidcrystal layer.

A liquid crystal inlet used when injecting a liquid crystal materialbetween the pair of first and second substrates is preferably providedat a side of the liquid crystal layer different from the first side end.

Fourth embodiment of the present invention provides a liquid crystaldisplaying device including at least: first and second substratesforming a pair, wherein at least the first substrate is constituted sothat light propagates inside it; a light source provided in the vicinityof the first side end of the first substrate; a multilayer structuresandwiched between the first and second substrates, which includes atleast a low refraction layer being lower in refractive index than thefirst substrate and being in direct contact with the first substrate, aplurality of color polarizing layers transmitting light of differentspecific wavelength band and being spatially arranged within each pixelregion, at least one or more phase difference layer; a reflectionstructure for reflecting at an angle perpendicular to, or nearlyperpendicular to, the boundary surface at least a part of light incomingin an oblique direction from the first substrate at an opposite side tothe low refraction layer with reference to the first layer: wherein aboundary surface between the first substrate and the low refractionlayer causes total reflection of the light incoming into the boundarysurface in an oblique direction.

A refractive index (nL) of the low refraction layer and a refractiveindex (nl) of the refractive index (nl) of the first substratepreferably meet a condition given by nL−nl<−0.01.

The reflection structure may be constituted of a layered structurehaving at least either of a plurality of protrusions or a plurality ofgrooves at an opposite side to the first substrate.

At least either of a plurality of the protrusions or a plurality of thegrooves preferably exist in the nearly same region as a displayingregion of the optical modulating display device.

The low refraction layer may be composed of a transparent material.

The low refraction layer may be composed of SiO₂ or MgF.

The first side end of the first substrate is preferably protrudedoutside compared with the side end of the second substrate.

The multilayer structure may be constituted so as to further include aseal member provided for attaching the pair of the first and the secondsubstrates in a peripheral region of a liquid crystal layer included inthe multilayer structure and a light blocking layer adjusted so as tooverlap the seal member viewed from a direction perpendicular to theboundary surface.

The multilayer structure may be constituted so as to further include aseal member provided so as to attach the pair of first and secondsubstrates in a peripheral region of the color polarizing layer and thephase difference layer as well as the liquid crystal layer.

A liquid crystal inlet used when injecting a liquid crystal materialbetween the pair of first and second substrates is preferably providedat a side of the liquid crystal layer different from the first side end.

Fifth embodiment of the present invention provides an optical modulatingdisplay device including at least: a first and second substrates forminga pair, wherein at least the first substrate is constituted so thatlight propagates inside the substrate; a light source provided in thevicinity of the first side end of the first substrate; a multilayerstructure sandwiched between the first and the second substrates, whichincludes a low refraction layer being lower in refractive index than thefirst substrate and further being in direct contact with the firstsubstrate, a first transparent electrode layer, a first insulatinglayer, a charged fine particle filled layer filled with charged fineparticles, and a second insulaive layer, as well as a second transparentelectrode layer; a reflection structure for reflecting at an angleperpendicular to, or nearly perpendicular to, the boundary surface atleast a part of light incoming in an oblique direction from the firstsubstrate at an opposite side to the low refraction layer with referenceto the first layer; wherein a boundary surface between the firstsubstrate and the low refraction layer causes total reflection of thelight incoming into the boundary surface in an oblique direction.

A refractive index (nL) of the low refraction layer and a refractiveindex (nl) of the first substrate preferably meet a condition given bynL−nl<−0.01.

The reflection structure may be constituted a layered structure havingat least either of a plurality of protrusions or a plurality of groovesat an opposite side to the first substrate.

Preferably, at least either of a plurality of the protrusions or aplurality of the grooves exist in the nearly same region as a displayingregion of the optical modulating display device.

The low refraction layer may be composed of a transparent material.

The low refraction layer may be composed of SiO₂ or MgF.

Sixth embodiment of the present invention provides a production methodfor an optical modulating display device, wherein the method comprisesthe steps of:

-   -   manufacturing an optical modulating device including a first        substrate constituted so that light propagates inside the        substrate; a second substrate forming a counterpart to the first        substrate, and a multilayer structure sandwiched between the        first and second substrates which contains an optical modulating        layer and a low refraction layer being in contact with the first        substrate and comprising a material lower in refractive index        than the first substrate; and    -   then, forming a reflection structure for reflecting at an angle        perpendicular to, or nearly perpendicular to, the boundary        surface at least a part of light incoming in an oblique        direction from the first substrate at an opposite side to the        low refraction layer with reference to the first substrate in        the optical modulating device.

The step of forming the reflection structure further comprises the stepsof:

-   -   applying a UV curing transparent resin on the opposite side of        the first substrate; and    -   pressing a metal mold having at least either of a plurality of        protrusions or a plurality of grooves on the UV curing        transparent resin, and while pressing, introducing ultraviolet        ray into the first substrate from the first side end of the        first substrate, followed by hardening the UV curing transparent        resin; and thereby printing the shape of the metal mold on the        UV curing transparent resin.

The step of forming the reflection structure further comprises the stepsof:

-   -   forming a transparent resin sheet at the opposite side of the        first substrate;    -   pressing the metal mold having at least either of a plurality of        protrusions or a plurality of grooves on the transparent resin        and applying pressure on it; and while pressing, heating the        transparent resin sheet up to a temperature of a glass        transition point or higher of the transparent resin sheet,        followed by printing the shape of the metal mold on the        transparent resin sheet;    -   cooling down the transparent resin sheet up to room temperature        while continuing to apply the pressure thereon; and    -   striping off the metal mold from the transparent resin sheet.

The step of forming the reflection structure is further followed by astep of dividing the optical modulating display device into a pluralityof individual optical modulating display devices.

The step of manufacturing the optical modulating device comprises a stepof assembling the pair of first and second substrates, and furthercomprises a step of previously creating a score at a side of the opticalmodulating layer in at least one of the first or the second substrateprior to the step of assembling.

Seventh embodiment of the present invention provides a production methodfor a liquid crystal displaying device, wherein the method comprises thesteps of:

-   -   manufacturing a liquid crystal displaying device including a        first substrate constituted so that light propagates inside the        substrate, a second substrate forming a counterpart to the first        substrate, and a multilayer structure sandwiched between the        first and second substrates which includes a liquid crystal        layer and a low refraction layer being in contact with the first        substrate and comprising a material lower in refractive index        than the first substrate; and    -   then, forming a reflection structure for reflecting at an angle        perpendicular to, or nearly perpendicular to, the boundary        surface at least a part of light incoming in an oblique        direction from the first substrate at an opposite side to the        low refraction layer with reference to the first substrate in        the liquid crystal device.

The step of forming the reflection structure further comprises the stepsof:

-   -   applying a UV curing transparent resin on the opposite side of        the first substrate; and    -   pressing a metal mold having at least either of a plurality of        protrusions or a plurality of grooves on the UV curing        transparent resin, and while pressing, introducing ultraviolet        ray into the first substrate from a first side end of the first        substrate; followed by hardening the UV curing transparent        resin, and thereby printing the shape of the metal mold on the        UV curing transparent resin.

The step of forming the reflection structure further comprises the stepsof:

-   -   forming a transparent resin sheet at the opposite side of the        first substrate;    -   pressing the metal mold having at least either of a plurality of        protrusions or a plurality of grooves on the transparent resin        and applying pressure thereon, and while pressing, heating the        transparent resin sheet up to a temperature a glass transition        point or higher of the transparent resin sheet, and followed by        printing the shape of the metal mold on the transparent resin        sheet;    -   cooling down the transparent resin sheet up to room temperature        while continuing to apply the pressure thereon; and    -   striping off the metal mold from the transparent resin sheet.

The step of forming the reflection structure is further followed by thestep of dividing the liquid crystal displaying device into a pluralityof individual liquid crystal displaying device.

The step of manufacturing the liquid crystal device comprises a step ofassembling the pair of first and second substrates, and furthercomprises a step of previously creating a score at a side of the liquidcrystal layer in at least either of the first or second substrate priorto the step of assembling.

As described above, the present invention provides an optical modulatingdisplay device. The optical modulating display device includes anoptical modulating layer and a pair of first and second substratessandwiching the optical modulating layer, where the first substrate isconstituted so that light propagates inside the substrate and the firstsubstrate includes a low refraction layer lower in refractive index on anear side of the optical modulating layer than the first substrate.

In conventional optical modulating display devices, a patternedstructure such as the above transparent electrode, polarizer, insulatingfilm, or color filter was in contact with inside of a pair of first andsecond substrates sandwiching an optical modulating layer, namely with asurface near the optical modulating layer. A refractive index of thetransparent electrode is 1.7 to 2.0. A refractive index of an insulatingfilm composed of polycarbonate is 1.58. A refractive index of the colorfilter is 1.49 to 1.55. These refractive indexes are higher than, oralmost consistent with, approximately 1.5 of the refractive index of theabove substrate. Therefore, the light incoming from the transparentelectrode side does not cause total reflection on the boundary surfacewith the substrate. When the patterned structure such as the colorfilter is in contact with the above substrate, scattering of lightoccurs between or on the patterns, which causes non-uniformity indisplay illumination as well as a faint display. These have beenproblems of the conventional optical modulating display device.

However, as the present invention, a low refraction layer lower inrefractive index than the substrate is provided at an inside of thefirst substrate constituted so that light propagates inside thesubstrate, namely at a near side of an optical modulating layer, wherebythe light incoming from the side face of the substrate causes totalreflection on a boundary surface between the first substrate and the lowrefraction layer. Therefore, incoming light can propagate up to anopposite side face to the side face of the substrate where the lightenters, namely an opposite side of light incoming side, thereby toensure a sufficient amount of guide light.

Also, the low refraction layer being lower in refractive index than thesubstrate is composed of a transparent material and constituted so as tobe in contact with the substrate on a smooth surface, thereby toeliminate non-uniformity in display illumination due to the scatteringof light.

Even when at least any one of a transparent electrode, a directing film,an insulating film, and a color filter is further arranged, the incominglight causes total reflection on the boundary surface between the abovesubstrate and the low refraction layer comprising the transparentmaterial. Therefore, degrees of freedom of selection of material of thetransparent electrode, the is directing film, the insulating film, andthe color filter expand, resulting in effect improving degrees offreedom of constitution of the optical modulating display device.

In addition, when thickness of the low refraction layer composed of thetransparent material is thinner than a wavelength, attenuation of theincoming light due to evanescent wave on the boundary surface betweenthe low refraction layer and the substrate occurs. To avoid occurrenceof the attenuation of the incoming light, the thickness of the lowrefraction layer composed of the transparent material is desirably 800nm or more. When the thickness of the low refraction layer is 800 nm ormore, the thickness of the low refraction layer of a wavelength ofvisible light or larger is ensured in an entire range of the wavelengthof the visible light, whereby the attenuation of the incoming light canbe securely avoided.

Relationship between a refractive index (nL) of the low refraction layerbeing lower in refractive index than the first substrate and arefractive index (nl) of the first substrate preferably meets acondition of nL−nl<−0.01. Namely, conditions of |nL−nl|>0.01 and nL<nlare preferably satisfied.

Specific methods and results of simulation performed by inventors of thepresent invention using an optical modulating (liquid crystal)displaying device 300 having a constitution illustrated in FIG. 2 willbe described below.

Namely, as illustrated in FIG. 2, a protruded portion 11 formed withconcavity and convexity in a protruded shape in a given interval isprovided on a surface 102 of an observer's side Z of a transparentsubstrate 1 of the observer's side 2 among a pair of substratessandwiching a liquid crystal layer and a transparent material layer 3having a flat surface is formed on a surface is 101 of the inside of thetransparent substrate 1, namely an opposite side to the observer's sideZ. A liquid crystal layer 8 is further suitably provided on a surface ofan opposite side to the transparent substrate 1 in the transparentmaterial layer 3, and a light reflector 405 comprising a mirror and thelike is provided on a surface of opposite side of the transparentmaterial layer 3 in the liquid crystal layer 8.

Then, a light source 12 is provided on a first side end of thetransparent substrate 1, and a light reflector 13 is arranged at a rearside of the light source 12. A first photo acceptance unit 120 isfurther provided on a second end of an opposite side to the first sideend of the transparent substrate 1 and a second photo acceptance unit130 is provided at a second end of the liquid crystal layer 8. The firstphoto acceptance unit 120 measures an amount of guide light which isquantity of light propagating through the transparent substrate 1, whilethe second photo acceptance unit 130 measures an amount of stray lighttransmitting through the liquid crystal layer 8.

The stray light is expressed by a dotted line in FIG. 2. The stray lightmeans light entering into the liquid crystal layer 8 without reachingthe light reflector 405 due to a large incoming angle, namely a largeangle from a direction of normal line of the liquid crystal layer 8,that is to say, the light reaching an opposite side of light incomingside without reflecting on the light reflector 405, or the lightreflected on the light reflector 405, and the light causing totalreflection on the boundary surface between the liquid crystal layer 8and the transparent material layer 3 to be trapped in the liquid crystallayer 8.

In the simulation, difference Δn of refractive index between arefractive index nl of the transparent substrate 1 and a refractiveindex nL of a member constituting the transparent material layer 3,namely Δn=(refractive index nL of the transparent material layer3)−(refractive index nl of the transparent substrate 1) is varied andthe amount of guide light and the amount of stray light are measured andanalyzed respectively. The result is shown in FIG. 3. The amount ofguide light is expressed by ♦ and a solid line and the amount of straylight is expressed by □ and a dotted line.

Namely, as shown in FIG. 3, it is found that the amount of guide lightdrastically drops when the difference Δn of the refractive index is 0 ormore. It is also found that the amount of stray light rapidly increaseswhen the difference Δn of the refractive index is 0 or more.

In the above simulation, the liquid crystal layer is selected as aphotochromatic layer, however, also in the case that, otherphotochromatic layer, for instance, a toner layer used in anelectrophoresis technique is used as a light modulating layer, it isfound that the amount of guide light drastically drops when thedifference Δn of the refractive index is 0 or more, and that the amountof stray light rapidly increases when the difference Δn of therefractive index is 0 or more.

Therefore, it is found to be necessary to meet a condition that thedifference Δn of the refractive index is less than 0, namely Δn<0 inorder to achieve the above object in the present invention.

On the other hand, even if the low refraction layer is actually formedinside the substrate, it is possible to cause error of approximately±0.01 in the refractive index of the low refraction layer due to surfaceroughness and non-uniformity in density in the transparent materiallayer constituting the low refraction layer. When the error ofapproximately ±0.01 in refractive index is caused, the difference Δnbetween the refractive index (nl) of the substrate and the refractiveindex (nL) of the low refraction layer is defined so as to meet acondition given by Δn=nL−nl<−0.01, which enables the refractive index tobe made lower than that of the substrate.

In consideration with the above results of the simulation and problemsin formation of layers, by defining the relationship between therefractive index of the substrate and the refractive index of the lowrefraction layer as nL−nl<−0.01, even if error of approximately ±0.01 iscaused in the refractive index of the low refraction layer, incominglight securely performs total reflection on the boundary surface betweenthe substrate and the low refraction layer, whereby a sufficient amountof guide light may be ensured within the substrate.

Also, by defining the relationship between the refractive index of thesubstrate and the refractive index of the low refraction layer asnL−nl<0, even if error of approximately ±0.01 is caused in therefractive index of the low refraction layer, incoming light securelycauses total reflection on the boundary surface between the substrateand the low refraction layer, whereby a sufficient amount of guide lightmay be ensured within the substrate.

Further, according to the present invention, a liquid crystal displayingdevice having the above constitution is provided, where the opticalmodulating layer comprises a liquid crystal layer, a first transparentsubstrate among a pair of the transparent substrates sandwiching theliquid crystal layer is constituted so that light propagates inside thesubstrate, and a surface facing the liquid crystal layer among the firsttransparent substrate is provided with a transparent material layercomprising the transparent material being lower in refractive index thanone of the transparent substrate.

In a conventional liquid crystal displaying device, the inside of a pairof transparent substrates sandwiching a liquid crystal layer, namely thesurface of a near side of the liquid crystal layer was in contact with apatterned structure such as the transparent electrode , polarizer, andcolor filter. The refractive indexes of the transparent electrode, thepolarizer (refractive index: 1.49 to 1.53), and the color filter arehigher than, or almost same as, the refractive index of the transparentsubstrate. Therefore, the light incoming from a side of the transparentsubstrate cannot cause total reflection on a boundary surface with thetransparent surface. Further, if the patterned structure such as thecolor filter is in contact with the transparent substrate, scattering oflight occurs between or on the patterns, which causes non-uniformity indisplay illumination as well as a faint display.

However, if a transparent material layer being lower in refractive indexthan the transparent substrate is provided inside the transparentsubstrate in the present invention, the light incoming from a first sideof the transparent substrate performs total reflection on the boundarysurface between the transparent substrate and the transparent materiallayer having the low refractive index. Thus, the incoming light can bepropagated up to an opposite side to the light incoming side, namely thesecond side, which is an 10 opposite side to the first side face intowhich the light enters, therefore sufficient a sufficient amount ofguide light may be ensured.

The transparent material layer being lower in refractive index than thetransparent substrate is in contact with the transparent substratethrough a smooth surface. Thus, the non-uniformity in displayillumination due to the scattering of light may be eliminated.

Further, even if any one of the transparent electrode, the polarizer,the directing film and the color filter is arranged inside thetransparent material layer being lower in refractive index than thetransparent substrate, light causes total reflection of light occurs onthe boundary surface between the transparent substrate and thetransparent material layer, therefore degrees of freedom of selection ofmaterial of the transparent electrode, the polarizer, the directingfilm, and the color filter expand and resulting in effect enhancing thedegrees of freedom of constitution of the liquid crystal displayingdevice.

The present invention is further constituted so that the lightpropagates inside the substrate and protrusions and/or grooves areprovided on the surface of the substrate opposite to the surface of thesubstrate where an optical modulating layer in this substrate exists.Namely, the protrusions and/or the grooves are provided on an upperportion of the substrate of an observer's side, namely the surface ofthe substrate of the observer's side, thereby allowing an angle outgoinginto the optical modulating layer to be controlled. Therefore, outgoinginto the optical modulating layer does not occur without occurrence oftotal reflection as prior art, whereby non-uniformity in displayillumination may be reduced. Further, thickness of the light guidingplate in the conventional front light is eliminated, thereby allowingdepth feel of the display to be eliminated and enabling a liquid crystaldisplaying device to be reduced in thickness and weight.

The low refraction layer being lower in refractive index than thesubstrate may be constituted of the material being lower in refractiveindex than the substrate and materials with high stability andreliablity among them are preferably used, for instance, SiO₂ or MgF ispreferable.

According to the present invention, a polarizing layer which transmitsonly specific polarized light between the low refraction layer beinglower in refractive index than the substrate and the liquid crystallayer may be formed. If the polarizing layer is arranged outside thesubstrate, namely surface side, non-polarized light from a light sourceenters into the liquid crystal layer, therefore black color may not bedisplayed. Also if the polarizing layer is provided directly on thelower part of the substrate, the refractive index of the polarizinglayer is nearly consistent with the refractive index of the substrate,therefore total reflection cannot occur to cause non-uniformity indisplay illumination. Thus, the polarizing layer may be provided betweenthe low refraction layer being lower in refractive index than thesubstrate and the liquid crystal layer. Such a constitution enables anon-polarized source light emerged from the substrate to be polarizedinto linear polarized light or circularly polarized light, therebyachieving secure display and reducing simultaneously non-uniformity indisplay illumination.

According to the present invention, a plurality of color polarizinglayers which transmits only specific polarized light of differentspecific wavelength band between the low refraction layer being lower inrefractive index than the substrate and the liquid crystal layer may bespatially arranged within 1 pixel. Thus, one layer simultaneously has apolarizing function and a color filter function, whereby the number oflamination of a laminated body arranged on a lower part of the substrateof the observer's side is allowed to be reduced and resulting in aneffect on simplification in manufacturing process.

According to the present invention, at least one phase difference layermay be further arranged between the polarizing layer or the colorpolarizing layer and the liquid crystal layer. If at least one phasedifference layer is arranged between the polarizing layer or the colorpolarizing layer and the liquid crystal layer, an optical compensationof the liquid crystal may be performed and thereby eliminating reverseof display and color heterogeneity in display.

Also according to the present invention, the optical modulating layer isconstituted of the liquid crystal layer, wherein the liquid crystallayer is sandwiched between a pair of first and second substrates, thelow refraction layer being lower in refractive index than the firstsubstrate is provided between the first substrate and the liquid crystallayer, and a laminated structure comprising a color filter layer whichtransmits light of different specific wavelength band, the polarizinglayer, at least one or more phase difference layer may be arrangedbetween the low refraction layer and the liquid crystal layer. That is,the color filter layer, the polarizing layer and at least one or morephase difference layer may be arranged in this order from the firstsubstrate side. Such arrangement and formation of the polarizing layerand the phase difference layer after process of forming a color filterlayer having many exposure processes improves reliability of device aswell as enables optical correction of the liquid crystal.

The present invention is characterized in that terminal surface of aside provided with a light source of the substrate constituted so thatlight propagates inside the substrate is protruded outside of the othersubstrate among the pair of substrates. As the present invention, onesubstrate terminal surface provided with the light source is protrudedoutside of the other substrate, thereby facilitating connection betweenthe light source and the substrate inside which light propagates andimproving optical usability.

As shown in FIG. 4, in the present invention, protrusions and/or groovesprovided on the first substrate may exist in a nearly consistent regionviewed in a plane against display region 500 of the optical modulatingdisplay device. This can reduce useless outgoing light into the opticalmodulating layer and improve optical usability and further scattering ofthe light resulting from the useless outgoing light is further curbedwhereby visual quality of the displaying device may be improved. Also itis preferable in view of improving optical usability that width of theregion provided with the protrusions and/or grooves in the substrate isnearly same as a width of outgoing light into the substrate in which thelight propagates inside the substrate.

According to the present invention, as shown in FIG. 5, an opticalmodulating layer comprises a liquid crystal layer, and a light blockinglayer may be provided on a seal material for attaching a pair ofsubstrates constituting the optical modulating display device. Thus,outgoing light into the optical modulating layer scatters by the sealmaterial and deterioration in visual quality can be prevented. The sealmaterial may also generally be constituted of epoxy resin or acrylicresin. Therefore, same as the polarizing layer and the color filterlayer, the seal material comprising the epoxy resin or acrylic resin hasrefractive index around 1.5 and is provided between the first substrateand the liquid crystal layer, and it is preferable in view of ensuringan amount of guide light that a low refraction layer being lower inrefractive index than the first substrate exists on the seal materialfor attaching the pair of the substrates.

According to the present invention, as shown in FIG. 6, an opticalmodulating layer comprises a liquid crystal layer and the polarizinglayer, the color polarizing layer, and the phase difference layer do notexist on the seal material for attaching the pair of substrates. Thus,peeling off of each layer constituting multilayer structure is curbedand thereby reliability may be improved.

According to the present invention, the optical modulating layercomprises the liquid crystal layer, and a liquid crystal inlet forinjecting liquid crystal material between the pair of the substrates maybe provided a side except the side provided with the light source in thefirst substrate constituted so that the light propagates inside thesubstrate. Thus, connection between the light source and the firstsubstrate in which the light propagates inside the substrate becomeseasy.

The present invention further provides a production method of an opticalmodulating display device, where after manufacturing an opticalmodulating device including an optical modulating layer, a pair of firstand second substrates sandwiching the optical modulating layer, and alow refraction layer which exists between the first substrate and theoptical modulating layer and which comprises a material being lower inrefractive index than the first substrate, thereafter the protrusionsand/or grooves are formed on an opposite side surface to the lowrefraction layer in the first substrate. When the protrusions and/or thegrooves are provided on a surface of an observer's side of the firstsubstrate before assembling the optical modulating display device, it ispossible to be unable to fix the substrate or possible to damage thesurface of the observer's side in production processes of the opticalmodulating device. However, according to the production method of theoptical modulating display device in the present invention, conventionalproduction processes for the optical modulating device may be applied,therefore the problems does not occur. Thus, reliability improves in theprocesses, and yield ratio improves.

The present invention also provides a production method for a liquidcrystal displaying device, where a transparent material layer comprisinga material being lower in refractive index than first transparentsubstrate constituted so that light ptopagetes inside the substrateamong a pair of first and second transparent substrates exist betweenthe first transparent substrate and the liquid crystal layer and aftermanufacturing a liquid crystal device having a structure sandwiching theliquid crystal layer between the second transparent substrate and thetransparent material layer, protrusions and/or grooves are formed on asurface of opposite side to the transparent material layer in the firsttransparent substrate. If the protrusions and/or grooves are provided ona surface of an observer's side of the first substrate before assemblingthe liquid crystal displaying device, it is possible to be unable to fixthe substrate or possible to damage the surface of the observer's side.However, according to the production method of the liquid crystaldisplaying device in the present invention, conventional productionprocesses for the liquid crystal device may be applied, therefore theproblems does not occur. Thus, reliability improves in the processes,and yield ratio enhances.

The present invention further provides a production method for anoptical modulating display device, where a low refraction layercomprising a material being lower in refractive index than the firstsubstrate on a surface of the first substrate comprising a transparentmaterial among a pair of first and second substrates exists between thefirst substrate and the optical modulating layer and after manufacturingan optical modulating device having a structure sandwiching the opticalmodulating layer between the low refraction layer and the secondsubstrate, UV curing transparent resin is applied on a surface ofopposite side to the low refraction layer in the first substrate,pressing a metal mold having the protrusions and/or grooves on the UVcuring transparent resin, and while pressing, introducing ultravioletray into the first substrate from a side terminal surface of the firstsubstrate, followed by hardening the UV curing transparent resin.According to the production method of the optical modulating displaydevice in the present invention, the protrusions and/or grooves may beformed only in a process of performing UV curing, resulting in allowingtime period of processes to be shortened and productivity of the opticalmodulating display device to be improved.

The present invention further provides a production method for anoptical modulating display device, where a low refraction layercomprising a material being lower in refractive index than the firstsubstrate on a surface of the first substrate among a pair of first andsecond substrates exists between the first substrate and the opticalmodulating layer and after manufacturing an optical modulating devicehaving a structure sandwiching the optical modulating layer between thepair of substrates, the protrusions and/or grooves are formed on theopposite side surface to the low refraction layer in the firstsubstrate, and then dividing the optical modulating device into aplurality of optical modulating display devices. Also in the presentproduction method, reliability of processes improves and yield ratioenhances. Further, simultaneous formation of a plurality of opticalmodulating display devices enables reduction of production cost. Alsopreferably, before assembling a pair of substrates, a score ispreviously formed on an opposite side to the optical modulating layer onone of the substrates or both substrates, which facilitates divisioninto a plurality of the optical modulating devices.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view of a conventional reflective liquidcrystal displaying device.

FIG. 2 is a cross-sectional view illustrating an example of a structureof a light guiding plate used in a simulation in the present invention.

FIG. 3 is a graph showing results obtained in the simulation in thepresent invention.

FIG. 4 is a top view of a displaying device illustrating relationbetween a display area and a region where protrusions exist, accordingto sixth embodiment of the present invention.

FIG. 5 is a cross-sectional view illustrating a liquid crystaldisplaying device according to ninth embodiment of the presentinvention.

FIG. 6 is a cross-sectional view of an optical modulating display deviceaccording to first embodiment of the present invention.

FIG. 7 is a cross-sectional view where a part of the optical modulatingdisplay device of FIG. 6 is enlarged.

FIG. 8 is a cross-sectional view of a liquid crystal displaying deviceaccording to second embodiment of the present invention.

FIG. 9 is a cross-sectional view where a part of the liquid crystaldisplaying device shown in FIG. 8 is enlarged.

FIG. 10A to 10F are views illustrating a production method of a liquidcrystal display portion according to third embodiment of the presentinvention.

FIG. 11A to 11D are views illustrating a production method of aprotruded portion of the liquid crystal display portion according to thethird embodiment of the present invention.

FIG. 12 is a cross-sectional view illustrating the liquid crystaldisplaying device according to fourth embodiment of the presentinvention.

FIG. 13A to 13D are views illustrating a production method of the liquidcrystal display portion according to fourth embodiment of the presentinvention.

FIG. 14 is a cross-sectional view illustrating the liquid crystaldisplaying device according to fifth embodiment of the presentinvention.

FIG. 15 is a cross-sectional view illustrating positional relationshipof a polarizing layer, phase difference layer, and seal agent of theliquid crystal displaying device according to eighth embodiment of thepresent invention.

FIG. 16A to 16D are views illustrating a production method of the liquidcrystal displaying device according to ninth embodiment of the presentinvention.

FIG. 17A to 17B are views illustrating a production method of the liquidcrystal displaying device according to tenth embodiment of the presentinvention.

FIG. 18 is a front view of a display apparatus according to thirteenthembodiment of the present invention.

BEST MODES FOR CARRYING OUT THE INVENTION FIRST EMBODIMENT

Embodiments of the present invention will be described below inreference to accompanied drawings in order to make clear objects,features and advantages of the present invention.

FIG. 6 is a cross-sectional view of an optical modulating display deviceaccording to first embodiment of the present invention. In the presentembodiment, an optical modulating layer is constituted of a layer filledwith charged fine particles. The optical modulating device in thepresent embodiment includes a pair of first substrate 400 and secondsubstrate 401, a multilayer structure sandwiched between the first andsecond substrates 400 and 401. The multilayer structure has a structurein which a low refraction layer 402 being lower in refractive index thanthe first substrate 400, a first transparent electrode layer 3-1 forapplying voltage, a first insulating layer 403-1, a charged fineparticle filled layer 404 filled with the charged fine particle, asecond insulating layer 403-2, and a second transparent electrode layer3-2 for applying voltage are laminated, at least viewed from anobserver's side, namely from an upper part of the drawing. The firstsubstrate 400 is constituted of the transparent substrate so that lightpropagates inside the substrate. The charged fine particles includeblack charged fine particles with positive polarity and white chargedfine particles with negative polarity.

Further, at least light source 12 and a reflector 13 for collectinglight on a first side are arranged on the first side of the firstsubstrate 400. Mirror finish is also applied on the first side of thefirst substrate 400 so as to remove flaw scattering light. A protrudedportion 11 for reflecting the light incoming from the first side of thefirst substrate 400 in a direction where the charged fine particlefilled layer 404 exists is further provided on a front surface of thefirst substrate 400, namely a surface of the observer's side. Thisprotruded portion 11 comprises a protrusion flat portion 103 a and aprotrusion tilted portion103 b.

Difference Δn of the refractive index between a refractive index (nL) ofthe low refraction layer 402 being lower in refractive index than thefirst substrate 400 and a refractive index (nl) of the first substrate400 is suitably set, thereby total reflection of the incoming lightentering from the side of the first substrate 400 may occur on a border,namely a boundary surface, between the first substrate 400 and the lowrefraction layer 402.

In conventional optical modulating display devices, patterned structuressuch as a transparent electrode, directing film, or color filter are incontact with inside of a transparent substrate, however refractiveindexes of the transparent electrode, the directing film, and colorfilter are higher than, or nearly same as, that of the transparentsubstrate, therefore total reflection of the light incoming from thetransparent substrate side does not occur on the boundary surfacebetween the transparent substrate and these patterned structures, andfurther when the patterned structures are in contact with thetransparent substrate as the color filter, scattering occurs between andon the patterns, which causes non-uniformity in display illumination.

However, the above structure in the present invention enables sufficientlight guiding of the incoming light up to an opposite side face oflight-incoming side which is second side face opposite to the first sideface of the transparent substrate constituting the first substrate 400and enables non-uniformity in display illumination to be eliminated.

Also even when the first transparent electrode 3-1 and the firstinsulating layer 403-1 are arranged inside, namely within, the lowrefraction layer 402, however, total reflection of the incoming lightoccurs on the boundary surface between the first substrate 400 and thelow refraction layer 402. Therefore, restriction on materials of thetransparent electrode, the insulating layer etc. is eliminated andthereby degrees of freedom of constitution of the optical modulatingdisplay device enhances. Thickness of the low refraction layer 402 isdesirably 800 nm or more.

By setting the thickness of the low refraction layer 402 as describedabove, the thickness becomes same as the wavelength or larger than thatin an entire range of visible light wavelength, and attenuation of theincoming light due to evanescent wave may be eliminated on the boundarysurface between the first substrate 400 and the low refraction layer402.

In the optical modulating display device in the present invention, alsothe above constitution is adopted, therefore the thickness of the lightguiding plate of front light is eliminated, which has been a problem ofprior art, as a result, depth feel of display may be eliminated andeffect on reduction in thickness and weight of the optical modulatingdisplay device is produced.

Display principle under an environment of poor external light such asnight time will be described below in accordance with the presentembodiment.

FIG. 7 is a cross-sectional view in which a part A of the opticalmodulating display device shown in FIG. 6 is enlarged. Light emergedfrom a light source 12 put light on enters into a first substrate 400from a first side of the first substrate 400, and total reflectionoccurs on a border surface between a projection flat portion 103 a andair. The incoming light of which total reflection has occurred is thenrefracted on the boundary surface between the first substrate 400 and aprotruded portion 11, which reaches the boundary surface between a lowersurface of the first substrate 400 (an opposite side surface to anobserver's side) and a low refraction layer 402, total reflection of theincoming light occurs again on this boundary surface. The incoming lightrepeats total reflection and refraction and propagates to an entiresurface within a display surface.

Light reaching a protrusion tilted portion 103b among propagatingincoming light reflects to an angle different from a prior reflectionangle, transmits the first substrate 400, a first and second transparentelectrode layers 3-1, and 3-2 and a first and second insulating layers403-1 and 403-2 and finally reaches a charged fine particle filled layer404. Then, if voltage is applied between the first and secondtransparent electrodes 3-1 and 3-2 so as to charge negatively a firsttransparent electrode 3-1 positioning near an observer's side and so asto charge positively a second transparent electrode 3-2 positioning infar place from the observer's side, a black charged fine particleshaving positive polarity in the charged fine particle filled layer 404moves to the observer's side. The light reaching the charged fineparticle filled layer 404 is absorbed and black print becomes possible.Adversely, if voltage is applied between the first and secondtransparent electrodes 3-1 and 3-2 so as to charge negatively the firsttransparent electrode 3-1 positioning near the observer's side and so asto charge positively the second transparent electrode 3-2 in the farplace from the observer's side, white charged fine particles havingpositive polarity in the charged fine particle filled layer 404 moves tothe observer's side. The light reaching the charged fine particle filledlayer 404 is absorbed and white print becomes possible. Contrasting ofdisplay and gradation sequence display depends on size and polarity ofvoltage applied between the first and the second transparent electrodes3-1 and 3-2.

A first substrate 400, the protruded portion 11 and a low refractionlayer 402 play a role substantially same as a light guiding function ofa front light and enables display in a dark place.

The present specific example is a displaying device performing black andwhite presentation, however color display may be performed by providinga color filter layer.

Then, a preparing method of the present embodiment will be specificallydescribed below.

At first, a UV curing material being lower in refractive index than aglass substrate, for instance, WR7709 with a refractive index of 1.38,which is produced by Kyouritsu Kagaku Co., was uniformly applied on thefirst substrate 400 comprising the glass substrate, hardened by exposingin ultraviolet ray to form a low refraction layer 402 having a uniformthickness of 2 μm or less and being lower in refractive index than theglass substrate. Then, a first transparent electrode layer 3-1comprising ITO (Indium Tin Oxide) and so on was formed on the lowrefraction layer 402, for instance, formed through a sputteringtechnique. Polycarbonate resin was further applied on the firsttransparent electrode layer 3-1 to form a first insulating layer 403-1.A second transparent electrode layer 3-2 and a second insulating layer403-2 were then formed on a second substrate 401 comprising the otherglass substrate in a same manner as the above-described method.

Pearl resin of diameter of 20 μm to 25 μm containing white or blackpigment was used as a charged fine particles. Titania powder was addedon the sphere surface for controlling charge property as a white chargedfine particles with positive polarity. Silica powder was added on thesphere surface for controlling the charge property as black charged fineparticles with negative polarity. These white and black fine particleswere mixed and stirred to charge both fine particles.

Then, a process of assembling a displaying portion will be described.

At first, in the previous process, the white charged fine particles andthe black charged fine particles were sparged at a ratio of white:black=1:1 on one substrate among the two substrates in which thelaminated structure was respectively formed. Then, an amount of spargingwas adjusted so that filling ratio of these charged fine particles,specifically a ratio of sum of volumes of all fine particles to volumebetween the substrates is 20%. The both substrates were then attached toprepare the displaying portion. Distance between both substrates was 250μm. The first substrate comprising the glass substrate positioned nearthe observer's side is protruded outside of the second substratecomprising an opposing glass substrate which makes it easy to arrangethe light source.

Then, a process of preparing the protruded portion 11 will be described.

A transparent resin sheet was arranged between a metal mold scatteredwith protrusions in a dotted form, of which cross-sectional shape isalmost saw-tooth appearance, or a metal mold formed with the protrusionsin a linear form and the displaying portion prepared prior to thepresent process. Pressure was then applied on the metal mold from aboveand the transparent resin sheet was pressed on the displaying portion.The transparent resin sheet was further heated up to a temperature of aglass transition point or higher to transform the transparent resinsheet into a protrusion shape using the metal mold as a template. Afterthat, while continuing to apply the pressure thereon, the transparentresin sheet was cooled down up to room temperature, and thereafter themetal mold was striped off from the displaying portion. As a result, theprotrusion shape of the metal mold was printed on the transparent resinsheet and the first substrate 400 comprising the glass substrate nearthe observer's side and the transparent resin sheet were in opticallyclose contact with each other. Thus, the protruded portion 11 was formedon the first substrate 400.

Also in the above process, pressurization treatment in an atmosphere isassumed, however the pressurization treatment in vacuum may beperformed. When the pressurization treatment in vacuum is carried out,air bubble is not printed on the transparent resin sheet, therefore thetreatment is effective in improving yield ratio.

As described above, a first side of the first substrate comprising theglass substrate near the observer's side is protruded outside of thesecond substrate comprising an opposite side glass substrate. Therefore,after the just previously described process, a light emitting diode 12as a light source emitting white light, a guide rod comprising atransparent material forming a source light into a linear source, and areflector 13 was arranged on the first side of the first substrate.Also, the side of protruded glass substrate was polished precisely orthe transparent resin layer was formed on the side thereby forming amirror finished surface. The above structure in the present embodimentis completed through these processes.

In the present embodiment, the glass substrate was used as the pair offirst and second substrates, however it is not necessary to berestricted to the glass substrate. For instance, a plastic substrate andso on may be used.

As described above, according to the present embodiment same as theembodiment, in the optical modulating display device, specifically inthe liquid crystal displaying device, the low refraction layer being incontact with an inner surface of the substrate where illuminating lightpropagates and being lower in refractive index than the substrate isprovided, thereby ensuring a sufficient amount of guide lightpropagating inside the substrate, reducing non-uniformity in displayillumination, further reducing in thickness and weight of a displayapparatus mounting these thereon to enable a high quality display.

SECOND EMBODIMENT

FIG. 8 is a cross-sectional view of an optical modulating display deviceaccording to second embodiment of the present invention. A liquidcrystal displaying device in the present embodiment includes amultilayer structure containing a liquid crystal layer and a pair offirst substrate 1 and second substrate 2 comprising transparentsubstrates sandwiching the multilayer structure. The multilayerstructure is constituted of a laminated structure comprising, viewedfrom an observer's side, namely from an upper part of the drawing, a lowrefraction layer 3 being lower in refractive index than the transparentsubstrate and comprising a transparent material layer, a color filterlayer 4 for color displaying, a polarizing layer 5 for transmitting onlyspecific polarized light component, a phase difference layer 6comprising at least one layer for performing an optical compensation ofliquid crystal, a transparent electrode layer 7 for applying voltagethereon, a liquid crystal layer 8, and a reflective electrode layer 9for reflecting incoming light in a direction of an observer, as well asa driving layer (active matrix device layer) 10 for driving the liquidcrystal.

A light source 12 and a reflector 13 for collecting light emerged fromthe light source 12 on first side are arranged on the first side of thefirst substrate 1 comprising the transparent substrate. Mirror finish isalso applied on the first side arranged with the light source 12 so asto remove flaw scattering the light. A protruded portion 11 forreflecting the light incoming from the first side of the first substrate1 in a direction of the reflective electrode layer 9 is further providedon a front surface of the first substrate 1 comprising the transparentsubstrate, namely on a surface of the observer's side.

Difference Δn of the refractive index between a refractive index (nL) ofthe low refraction layer 3 being lower in refractive index than thefirst substrate 1 comprising the transparent substrate and a refractiveindex (nl) of the first substrate 1 is suitably set, thereby allowingtotal reflection of the incoming light entering from the first side ofthe first substrate 1 to occur on a border between the first substrate 1and the low refraction layer 3, namely a boundary surface therebetween.

In a conventional optical modulating display device, patternedstructures such as a transparent electrode, a directing film, or a colorfilter is in contact with inside of a transparent substrate, howeverrefractive indexes of the transparent electrode, the directing film, andcolor filter are higher than, or nearly same as, refractive index of thetransparent substrate, therefore total reflection of the light incomingfrom the transparent substrate side does not occur on the boundarysurface between the transparent substrate and these patternedstructures, and further when the patterned structure such as the colorfilter is in contact with the transparent substrate, scattering occursbetween and on the patterns, which causes non-uniformity in displayillumination.

Also, the above structure in the present invention enables sufficientlight guiding of the incoming light up to an opposite side face to alight-incoming side which is the second side opposite to the first sideof the transparent substrate constituting the first substrate 1 and alsoenables non-uniformity in display illumination to be eliminated.

The transparent electrode layer 7 and the color filter layer 4 are alsoarranged inside, namely within, the transparent material layer 3,however, total reflection of the incoming light occurs on the boundarysurface between the first substrate 1 comprising the transparentsubstrate and the low refraction layer 3 comprising the transparentmaterial layer. Therefore, restriction on materials of the transparentelectrode, the directing film and the color filter is eliminated anddegrees of freedom of constitution of the liquid crystal displayingdevice enhances. Thickness of the low refraction layer 3 comprising thetransparent material layer is desirably 800 nm or more.

By setting the thickness of the low refraction layer 3 as describedabove, the thickness becomes same as or larger than the wavelength in anentire range is of visible light wavelength, and attenuation of theincoming light due to evanescent wave may be eliminated on the boundarysurface between the first substrate 1 and the low refraction layer 3.

In the liquid crystal displaying device in the present invention, alsothe above constitution is adopted, therefore the thickness of the lightguiding plate of a front light is eliminated, which has been a problemof prior art, as a result, depth feel of display may be eliminated,which is effective in reducing in thickness and weight of a liquidcrystal displaying device.

As described above, also in the example, the polarizing layer 5 fortransmitting only at least specific polarized light between the lowrefraction layer 3 and the liquid crystal layer 8 was arranged so as notto be in direct contact with a lower part of the low refraction layer 3comprising the transparent material layer.

In other words, the light emerged from the light source 12 isnon-polarized light. In the case that the polarizing layer 5 is notprovided between the first substrate 1 and the liquid crystal layer 8,the non-polarized light is entered into the liquid crystal layer 8.Therefore, normal display becomes difficult. Particularly, black displayis difficult.

Even though the polarizing layer 5 is provided, in the case that thepolarizing layer 5 is provided so as to be in direct contact with alower part of the first substrate 1 comprising the transparent substratefunctioning as a light guiding layer, a refractive index of thepolarizing layer 5 is almost same as refractive index of the transparentsubstrate constituting the first substrate 1, therefore total reflectionof the incoming light cannot occur on the boundary surface between thefirst substrate 1 and the polarizing layer 5, which causesnon-uniformity in display illumination.

Thus, the polarizing layer 5 is preferably provided between the lowrefraction layer 3 and the liquid crystal layer 8 so as not to be indirect contact with the lower part of the low refraction layer 3. Such astructure allows the non-polarized source light emerged from thetransparent substrate to polarize into linear polarized light orcircularly polarized light, thereby to enable display to ensure and tosimultaneously enable reduction of non-uniformity in displayillumination.

The phase difference layer 6 is further arranged on the lower part ofthe polarizing layer 5, therefore an optical compensation of the liquidcrystal may be performed and inversion of display and color irregularitymay be eliminated.

Display principle under an environment of poor external light such asnight time will be described below in accordance with the presentembodiment.

FIG. 9 is a cross-sectional view in which a part A of a liquid crystaldisplaying device shown in FIG. 8 is enlarged. Light emerged from alight source 12 put light on enters within a first substrate 1 from afirst side of the first substrate 1, and total reflection of the lightoccurs on a border surface between projection flat portions 103 a andair.

The incoming light of which the total reflection has occurred thenrefracts on a boundary surface between the first substrate 1 comprisinga transparent substrate and a protruded portion 11, and reaches theboundary surface between a lower surface of the first substrate 1 (asurface of opposite side to an observer's side surface) comprising thetransparent substrate and a low refraction layer 3, and thereafter totalreflection of the incoming light occurs again on this boundary surface.The incoming light repeats the total reflection and refraction andpropagates to an entire surface within a display surface.

Light reaching a protrusion tilted portion 103b among propagatingincoming light reflects to an angle different from a prior reflectionangle, and transmits the first substrate 1 comprising the transparentsubstrate. The transmitted light propagates to a color filter layer 4, apolarizing layer 5, a phase difference layer 6, and a liquid crystallayer 8, and reflects on a reflective electrode layer 9, and transmitsagain the liquid crystal layer 8, the phase difference layer 6, thepolarizing layer 5, the color filter layer 4, a low refraction layer 3comprising a transparent material layer, and the first substrate 1comprising the transparent substrate as well as a protruded portion 11to be recognized by an observer. Contrasting of display, gradationsequence display, and color display are controlled by voltage applied onliquid crystal.

In the present embodiment like this, a first substrate 1 comprising thetransparent substrate, a protruded portion 11 and a first substrate 3comprising the low refraction layer comprising the transparent materiallayer play a role substantially the same as a light guiding function ofa front light and enables display in a dark place.

As a modified example of the above example, also in the present specificexample, the low refraction layer 3 comprising the transparent materiallayer is provided so as to be in contact with the lower surface of thefirst substrate 1 comprising the transparent substrate. However, thislow refraction layer 3 may be constituted of any one of the polarizinglayer 5, the phase difference layer 6 or the transparent electrode layer7. Namely, as a condition that any one of the polarizing layer 5, thephase difference layer 6 or the transparent electrode layer 7 is lowerin refractive index than the first substrate 1 comprising thetransparent substrate without being provided with the transparentmaterial layer 3, this layer plays a role as the low refraction layer,whereby it is possible to constitute so that total reflection of anincoming light occurs on the boundary surface between the low refractionlayer 3 constituted of any one of the polarizing layer 5, the phasedifference layer 6 or the transparent electrode layer 7 and the firstsubstrate 1 comprising the transparent substrate. Namely, such aconstitution enables constitution so that any one of the polarizinglayer 5, the phase difference layer 6, or the transparent electrodelayer 7 combine function and action provided by a low refractive indexof the transparent material layer 3 without using the transparentmaterial layer 3.

As a further modified example of the present embodiment, the polarizinglayer 5 and the color filter layer 4 may be replaced with at least onecolor polarizing layer transmitting only specific polarized light ofdifferent specific wavelength band. It is preferably to spatiallyarrange a plurality of the color polarizing layer within one pixel.Namely, the color polarizing layer is provided, whereby a single layeris in charge of a polarizing function and a color filter function.Therefore, the number of layers of a laminated body arranged between thefirst substrate 1 comprising the transparent substrate positioned at anobserver's side and a liquid crystal layer 8 is reduced to be effectivein simplification of a production process.

As described above, according to the present embodiment same as theabove embodiment, in the optical modulating display device, specificallya liquid crystal displaying device, the low refraction layer being incontact with an inner surface of the substrate where illuminating lightpropagates and being is lower in refractive index than the substrate isprovided, thereby ensuring a sufficient amount of guide lightpropagating inside the substrate, reducing non-uniformity in displayillumination, further reducing in thickness and weight of a displayapparatus mounting these thereon to enable a high quality display.

THIRD EMBODIMENT

Then, a preparing method of the present embodiment will be specificallydescribed below.

FIG. 10A to 10G are cross-sectional views illustrating a productionmethod of an optical modulating (liquid crystal) displaying device in anembodiment according to the present invention, where FIG. 10A to 10Cshow manufacturing processes of a first glass substrate in a liquidcrystal displaying device combining a light guiding function of a frontlight and FIG. 10D to 10F show manufacturing processes of a second glasssubstrate and assembling processes of a liquid crystal displayingportion. FIG. 10G also shows a manufacturing process of a protrudedportion in the liquid crystal displaying device in the presentinvention. As a flow of schematic processes of production, the liquidcrystal displaying portion 14 is first prepared and the protrudedportion 11 is then formed on the liquid crystal displaying portion 14.

As illustrated in FIG. 10A, after uniformly applying a UV curingtransparent material being lower in refractive index than the glasssubstrate 1 on the first transparent glass substrate 1, the material byperforming ultraviolet ray exposure was hardened, followed by forming alow refraction layer 3 comprising the transparent material layer havingeven thickness of 2 μm or is less. Then, a color resist of R (red) wasapplied on the low refraction layer 3 comprising the transparentmaterial layer, followed by performing a pattern exposure, development,and fixing to form a red (R) layer 4 a of a color filter. By performingthe same operations, a G (green) layer 4b and a blue (B) layer 4 c wereformed and a color filter layer 4 spatially divided whose thickness isapproximately 1 μm was formed. In the case that a surface of the formedcolor filter layer 4 is not smooth, an overcoat layer comprising atransparent resin was formed on the surface of the color filter layer 4to make the surface smooth.

As illustrated in FIG. 10B, after forming a material with anisotropy inabsorption, for instance, a directing layer 5 b for directing adichromatic pigment, on the color filter layer 4, a UV curing resincontaining the dichromatic pigment was uniformly applied to perform aultraviolet ray exposure. Thereby a UV curing resin layer 5a where thedichromatic pigment is in a uniaxial orientation was formed. The useddichromatic pigment is a mixture of dichromatic pigments absorbing cyan,magenta, yellow and so on, and this mixture absorbs almost entire rangeof visible light. Further the dichromatic pigment is in the uniaxialorientation, thereby occurring anisotropy in absorption of light to forma laminated body of the UV curing resin layer 5a in the uniaxialorientation and the directing layer 5 b for directing the dichromaticpigment. The laminated body comprising the directing layers 5 a and 5 bplay a role as a polarizing layer 5. Namely, the polarizing layer 5 inthe present embodiment comprises a double layered structure of thedirecting layer 5 b for directing the dichromatic pigment and the UVcuring resin layer 5 a containing the dichromatic pigment.

Processes shown in FIG. 10C, after applying and forming a directinglayer 6 b for directing liquid crystalline monomer on the UV curingresin layer 5 a with the uniaxial orientation, the liquid crystallinemonomer was hardened with ultraviolet ray, followed by forming auniaxial anisotropic layer 6 a of a birefringence amount ofapproximately 275 nm at a wavelength of 550 nm. An optical axis of theuniaxial anisotropic layer 6 a depends on a orientating direction of thedirecting layer 6 b, and the optical axis of the uniaxial anisotropiclayer 6 a is consistent with an axis rotated approximately 15 degrees inclockwise direction with reference to an absorbing axis of thepolarizing layer 5.

By repeating operations same as the above operations, after applying andforming a directing layer 6 c for directing the liquid crystallinemonomer on the directing layer 6 d, the liquid crystalline monomer washardened with ultraviolet ray to form a uniaxial anisotropic layer 6 cof birefringence amount of approximately 137 nm at a wavelength 550 nm.An optical axis of the uniaxial anisotropic layer 6 c is consistent withan axis rotated about 75 degree in clockwise direction from theabsorbing axis of the polarizing layer 5.

A phase difference layer 6 comprising these four layers, specificallythe directing layer 6 b, the uniaxial anisotropic layer 6 a, thedirecting layer 6 d and the uniaxial anisotropic layer 6 c functions asa wide range quarter wave plate for converting linear polarized lightemerged from the polarizing layer 5 into circularly polarized lightalmost over entire range of visible light.

In the present embodiment, the phase difference layer 6 including twouniaxial aniotropic layers 6 a and 6 c is used excluding the directinglayers 6 b and 6 d, however it is not restricted to this, and the phasedifference layer 6 may include a single uniaxial anisotropic layer. Inthis case, a direction of the optical axis and the birefringence amoungof the phase difference layer 6 are suitably adjusted.

As shown in FIG. 10D, a transparent electrode layer 7 comprising ITO(Indium Tin Oxide) and so on is formed on the phase difference layer 6through a sputtering technique.

As shown in FIG. 10E, a driving layer 10 was formed which is arranged onan array with an active device for driving each pixel on the secondglass substrate 2, and a reflective electrode layer 9 was further formedwhich comprises a metal reflective plate in concavity and convexityshape on the upper surface of the driving layer 10.

Assembling process of a liquid crystal display portion 14 will bedescribed in reference to FIG. 10F. In the prior processes, the firstand second substrates 1 and 2 having respectively the first and secondmultilayer structures were drafted. On the surface of the transparentelectrode layer 7 in the first multilayer structure formed on the firstsubstrate 1 shown in FIG. 10D, a first directing layer 18 a fordirecting liquid crystal was formed. On the surface of the reflectiveelectrode layer 9 in the second multilayer structure formed on thesecond substrate 1 shown in FIG. 10E, a second directing layer 18 a fordirecting the liquid crystal was formed. A direction of orientation ofthe first directing layer 18 a is a direction of approximately 35 degreein clockwise direction with reference to the absorbing axis of thepolarizing layer 5 and a direction of orientation of the seconddirecting layer 18 b is a direction of approximately 37 degree incounterclockwise direction.

Then, a spacer (not shown) and seal agent 20 were sandwiched betweenboth substrates 1 and 2, which were attached so as to make clearance ofapprox. 4 μm between both substrates 1 and 2. Liquid crystal 19 wasfinally injected into the clearance from an inlet, and the clearance wasfilled with the liquid crystal 19, thereafter the inlet was sealed tocomplete the liquid crystal displaying portion 14, where the liquidcrystal layer 8 comprises the liquid crystal 19, the spacer and the sealagent 20, the first and second directing layers 18 a and 18 bsandwiching these.

In addition, a thing to be kept in mind is that, though it is not shownin drawings, a first glass substrate 1 a of the liquid crystaldisplaying portion 14 is protruded outside of the second glass substrate2 a which facilitates arrangement of the light source 12.

Preparing processes of the protruded portion 11 of the liquid crystaldisplaying device will be described in reference to FIG. 11A to 11D.

As shown in FIG. 11A, the liquid crystal displaying portion 14 preparedprior to the present process was arranged so as to position the firstglass substrate 1 a on the second glass substrate 1 b. A metal mold 15scattered with protrusions in a dotted form of which cross-sectionalshape is nearly saw-tooth appearance or formed in a linear shape wasprepared. A transparent resin sheet 16 was arranged between the liquidcrystal displaying portion 14 and the metal mold 15, where thetransparent resin sheet 16 is arranged on the first glass substrate 1 a.

As shown in FIG. 11B, pressure 17 was applied toward the transparentresin sheet 16 from upper part of the metal mold 15, and the transparentresin sheet 16 was pressed on a surface of the liquid crystal dispalyingportion 14, namely on a surface of the first glass substrate la.Thereafter, the transparent resin sheet 16 was heated up to atemperature of glass transition point or higher, and was transformedinto a protruded shape of the metal mold 15.

As shown in FIG. 11C, in a state that pressure 17 is being applied, thetransparent resin sheet 16 was cooled down to room temperature, and thenthe metal mold 15 was striped off from the liquid crystal displayingportion 14, namely from the transparent resin sheet 16. As a result, onthe surface of the transparent resin sheet 16, the protruded shape ofthe metal mold 15 was printed, and the first glass substrate 1 a and thetransparent resin sheet 16 are further in optically close contact witheach other. Thereby, the protruded portion 11 was formed on the firstglass substrate 1 a.

In the case that the transparent resin sheet 16 and the first glasssubstrate 1 a are not attached well, the transparent resin sheet 16 andthe first glass substrate 1 a are attached using an adhesive agent ofwhich refractive index is almost consistent with that of the first glasssubstrate 1 a, or an s adhesive agent of which refractive index isalmost consistent with that of the transparent resin sheet 16.

In the present embodiment, after liquid crystal 19 was injected into theliquid crystal displaying portion 14, the protruded portion 11 wasformed. However, the protruded portion 11 may be formed before theliquid crystal is injected into the liquid crystal displaying portion14.

Also, a pressurization treatment was performed in the atmosphere in theabove process, however the pressurization treatment may be performed invacuum. If the pressurization treatment is performed in vacuum, airbubble is not printed on the transparent resin sheet 16, thereby thetreatment is effective in improving yield ratio.

As shown in FIG. I ID, a light emitting diode 12 for emitting whitelight, a guide rod (not shown) comprising the transparent material forforming source light into linear light source from the light emittingdiode 12, and reflector 13 are arranged on the first side 1 b of thefirst glass substrate 1 a, namely a protruded portion outside of thesecond glass substrate 2 a. Or instead of that, the first side 1 b ofthe first glass substrate 1 a is precisely polished, or the transparentresin layer (not shown) was formed on the first side 1 b to form amirror finished surface. Through the above series of processes shown inFIGS. 10A to 10F and FIGS. 11A to 11D, a structure of the liquid crystaldisplaying device according to the present embodiment is completed.

According to the present embodiment, the first and second glasssubstrates 1 a and 2 a were used as the first and second transparentsubstrates 1 and 2, however it is not necessary to be restricted tothis, for instance, a transparent plastic substrate may be used as thefirst and second transparent substrates 1 and 2.

Also according to the present embodiment, at least viewed from anobserver's side (from upper part of the drawing), a low refraction layer3 comprising the transparent material layer, a color filter layer 4, apolarizing layer 5, a phase difference layer 6, a transparent electrodelayer 7, liquid crystal lo layer 8, and a reflective electrode layer 9as well as a driving layer 10 are laminated in this order. However, ifthe polarizing layer 5 exists at a position above the phase differencelayer 6, namely at a closer position to the first transparent substrate1, the same effect as the present embodiment is obtained. Therefore, asa modified example of the present embodiment, for instance, is viewedfrom the observer's side (from the upper part of the drawing), thetransparent material layer 3, the polarizing layer 5, the color filterlayer 4, the phase difference layer 6, the transparent electrode layer7, the liquid crystal layer 8, and the reflective electrode layer 9 aswell as the driving layer 10 may be laminated in this order. Or as afurther modified example of the present embodiment, for instance, viewedfrom the observer's side, the transparent material layer 3, thepolarizing layer 5, the phase difference layer 6, the color filter layer4, the transparent electrode layer 7, the liquid crystal layer 8, andthe reflective electrode layer 9 as well as the driving layer 10 may belaminated in this order.

In addition, as a further modified example of the present embodiment, ametal lattice formed with a pitch of visible wavelength or lower may beused instead of the polarizing layer 5. A color filter of complementarycolor base, typically, Y (yellow), M (magenta), and C (cyan) may be usedinstead of the color filter layer 4.

As described above, according to the present embodiment same as theabove embodiment, in the optical modulating display device, specificallythe liquid crystal displaying device, the low refraction layer being incontact with the inner surface of the substrate inside whichilluminating light propagates and being lower in refractive index thanthe substrate is provided, thereby ensuring a sufficient amount of guidelight propagating inside the substrate and reducing non-uniformity indisplay illumination, and further reducing i thickness and weight of adisplay apparatus mounting these thereon to enable a high qualitydisplay.

FOURTH EMBODIMENT

FIG. 12 is a cross-sectional view illustrating a liquid crystaldisplaying device according to fourth embodiment of the presentinvention. A structure of the liquid crystal displaying device accordingto the fourth embodiment shown in FIG. 12 is different in a pointdescribed below from the above structure of the liquid crystaldisplaying device according to the second embodiment shown in FIG. 8. Inaddition, in a constitution of the liquid crystal displaying deviceshown in FIG. 12, the same symbols as the symbols used in FIG. 8 aregiven to the same portions as the constitution according to the secondembodiment shown in FIG. 8.

As seen in comparison of the structure shown in FIG. 12 with thestructure shown in FIG. 8, in the structure of the liquid crystaldisplaying device according to the fourth embodiment shown in FIG. 12, asingle color polarizing layer 22 having a polarizing function and acolor displaying function together is provided instead of a polarizinglayer 5 and a color filter layer 4 having the above structure of theliquid crystal displaying device according to the second embodimentshown in FIG. 8. Thereby, in addition to the effect described in thesecond embodiment, an effect of reducing the number of lamination and aneffect on simplification of production process involved in this areobtained.

A part of production process of the liquid crystal displaying deviceaccording to the present embodiment is shown below in reference to FIG.13A to 13D.

As shown in FIG. 13A, after uniformly applying a UV curing transparentmaterial being lower in refractive index than a glass substrate 1 a onthe first transparent glass substrate 1 a, the material was hardened byperforming a ultraviolet ray exposure to form a low refraction layer 3comprising the transparent material layer having even thickness of 2 μmor less.

Then, after forming a material with anisotropy in absorption, forinstance, a directing layer 22 d for directing a dichromatic pigment, onthe low refraction layer 3 comprising the transparent material layer, aUV curing resin containing the dichromatic pigment was uniformly appliedto perform the ultraviolet ray exposure. Thereby, a UV curing resinlayer 22 d where the dichromatic pigment is in a uniaxial orientationwas formed. The used dichromatic pigment is a mixture of dichromaticpigments absorbing cyan, magenta, yellow and so on, and this mixtureabsorbs almost entire range of visible light.

Further liquid crystalline monomer mixture 22 a with UV curing propertycontaining the dichromatic pigment transmitting red light (R) wasuniformly applied thereon.

As shown in FIG. 13B, after arranging a patterned mask 23 in a stripeshape above the substrate, the liquid crystalline monomer mixture 22 awith UV curing property containing the dichromatic pigment wasselectively exposed with ultraviolet ray using the patterned mask 23.

Then, as shown in FIG. 13C, the used patterned mask 23 was removed,portions which have not been exposed in the liquid crystalline monomer22 a were further removed through development to form a patterned red(R) color polarizing layer 22 a.

As shown in FIG. 13D, after applying a liquid crystalline monomermixture 22 b containing the dichromatic pigment transmitting green light(G) on the red (R) color polarizing layer 22 d, a patterned mask (notshown) in a stripe shape was arranged above the substrate to selectivelyexpose with ultraviolet ray the liquid crystalline monomer mixturecontaining the dichromatic pigment transmitting green light (G) usingthe patterned mask. Then, the used patterned mask was removed, andportions which have not been exposed in the liquid crystalline monomer22 b were further removed through the development to form a patternedgreen (G) color polarizing layer 22 b, where the patterned green (G)color polarizing layer 22 b is spatially separated from the patternedred (R) color polarizing layer 22 a.

Then, after applying a liquid crystalline monomer mixture 22 ccontaining a dichromatic pigment transmitting blue light (B) on the blue(B) color polarizing layer 22 d, a patterned mask (not shown) in astripe shape was arranged above the substrate to selectively expose withultraviolet ray the liquid crystalline monomer mixture containing thedichromatic pigment transmitting blue light (B) using the patternedmask. Then, the used patterned mask was removed, and portions which havenot been exposed in the liquid crystalline monomer 22 c were furtherremoved through the development to form a patterned blue (B) colorpolarizing layer 22 c, where the patterned blue (B) color polarizinglayer 22 c is spatially separated from the patterned green (G) colorpolarizing layer 22 b.

Through the above processes, a color polarizing layer 22 comprising thered (R) color polarizing layer 22 a, the green (G) color polarizinglayer 22 b, and the blue (B) color polarizing layer 22 c which arespatially separated was formed.

Then, by going through the same processes as the second embodiment, thestructure of the liquid crystal displaying device according to thepresent embodiment is completed.

As described above, according to the present embodiment same as theabove embodiment, in the optical modulating display device, specificallythe liquid crystal displaying device, the low refraction layer being incontact with the inner surface of the substrate inside whichilluminating light passes on and being lower in refractive index thanthe substrate is provided, thereby ensuring a sufficient amount of guidelight propagating inside the substrate and reducing non-uniformity indisplay illumination, and further reducing in thickness and weight of adisplay apparatus mounting these thereon to enable a high qualitydisplay.

FIFTH EMBODIMENT

The present invention may adopt a constitution in which a displayingdevice is illuminated from a second substrate side opposite to a firstsubstrate of an observer's side, namely a back light type constitution,as a substitute for a constitution that the displaying device isilluminated from the first substrate of the observer's side.

FIG. 14 is a cross-sectional view of an optical modulating displaydevice according to fifth embodiment of the present invention. Theoptical modulating display device in the present embodiment will bedescribed using a liquid crystal displaying device as an example. Aliquid crystal displaying device comprises a multilayer structurecontaining a liquid crystal layer 8 and a pair of first transparentsubstrate 2 and second transparent substrate 1 sandwiching themultilayer structure. The multilayer structure is constituted of alaminated body comprising a first polarizing layer 5-1, a color filterlayer 4, a first transparent electrode layer 7-1, a liquid crystal layer8, a second transparent electrode layer 7-2, and a second polarizinglayer 5-2 as well as a low refraction layer 402 comprising a transparentmaterial layer being lower in refractive index than the firsttransparent substrate 2, in this order viewed from the observer's side.

Also, at least a light source 12 and a reflector 13 for collectingsource light from the light source 12 on a first side of the firsttransparent substrate 2 are arranged on the first side of the firsttransparent substrate 2. Mirror finish is also applied on at least thefirst side of the first transparent substrate 2 so as to remove flawscattering the light.

A protruded portion 11 for reflecting the light incoming from the firstside of the first transparent substrate 2 in a direction of the liquidcrystal layer 8 is further provided on a surface of the firsttransparent substrate 2.

A reflector 405 is further provided outside the first transparentsubstrate 2 and thereby reflecting the light leaked from a protrudedportion 11 in a direction of the liquid crystal layer 8.

The structure of the liquid crystal displaying device according to thepresent embodiment was prepared by forming each layer in the same manneras a forming process described in the third embodiment and assemblingthem in a same manner. However, each absorption axis of the first andsecond polarizing layers 5-1 and 5-2 is at right angles to each otherand a orientating direction of the liquid crystal layer 8 is furtherconsistent with either of absorption axis of the polarizing layer. Whenassembling the liquid crystal displaying portion, a liquid crystal inletis also provided at a side of an opposite direction to a light sourcecontacting surface, thereby facilitating connection of the light source12 and the first transparent substrate 2.

As described above, according to the same embodiment as the aboveembodiment, in the optical modulating display device, specifically theliquid crystal displaying device, the low refraction layer being incontact with the inner surface of the substrate inside whichilluminating light propagates and being lower in refractive index thanthe substrate is provided, thereby ensuring a sufficient amount of guidelight propagating inside the substrate, reducing non-uniformity indisplay illumination, further reducing in thickness and weight of adisplay apparatus mounting these thereon to enable a high qualitydisplay.

SIXTH EMBODIMENT

The present embodiment is the same constitution as the above embodiment,however as shown in FIG. 4, a protruded portion 11 is formed in adisplaying region 500, namely in an almost same region 501 as the regionused for display.

Thus, meaningless light emerged into an optical modulating layer isreduced, thereby to enable optical usability to be improved. Scatteredlight resulting from the meaningless emerged light is furtherrestrained, whereby visual quality may be improved. A displaying devicein the present embodiment may be prepared in the same manner as theabove third embodiment. However, a region where protrusions exist ofwhich the cross-sectional shape formed on a metal mold 15 is almostsaw-tooth appearance is nearly same as the displaying region, and aregion where the protrusions exist when pressing the metal mold 15 on adisplaying portion 14 is consistent with the displaying region, namelyis performed an overlay alignment therewith, thereby to prepare thedisplaying device.

As described above, according to the same embodiment as the aboveembodiment, in the optical modulating display device, specifically theliquid crystal displaying device, the low refraction layer being incontact with the inner surface of the substrate inside whichilluminating light propagates and being lower in refractive index thanthe substrate is provided, thereby ensuring a sufficient amount of guidelight propagating inside the substrate, reducing non-uniformity indisplay illumination, further reducing in thickness and weight of adisplay apparatus mounting these thereon to enable a high qualitydisplay.

SEVENTH EMBODIMENT

A structure of a liquid crystal displaying device according to thepresent embodiment is illustrated in FIG. 5. The structure of the liquidcrystal displaying device shown in FIG. 5 is almost same as thestructure obtained through the production method according to the thirdembodiment described in reference to FIGS. 10A to 10F and FIGS. 11A to11D, however it is different in a point that a light blocking layer 502for hiding a seal agent 20 is selectively formed between a lowrefraction layer 3 and a color filter layer 4, where the light blockinglayer 502 is arranged so as to be adjusted with the seal agent 20,namely to overlap the same, viewed as a plane. Thus, by providing thelight blocking layer 502, the seal agent prevents outgoing light into anoptical modulating layer, namely a liquid crystal layer 8, fromscattering, thereby deterioration of visual quality may be prevented. Inaddition, in FIG. 5, a region expressed in black in the color filterlayer 4 shows that color polarizing layers of three primary colorsconstituting the color filter layer 4 are spatially separated from eachother.

In a production method described in the above embodiment, the structureaccording to the present embodiment was prepared by forming atransparent material layer being lower in refractive index than asubstrate thereafter applying a black resist, performing a patternexposure, developing, and fixing to form the light blocking layer, thenlaminating each layer as shown in the above embodiment.

In addition, also in the case that a light absorbing agent such as blackpigment is mixed to the seal agent instead of the light blocking layer502, the same effect may be obtained as the present embodiment.

As described above, according to the present embodiment same as theabove embodiment, in the optical modulating display device, specificallythe liquid crystal displaying device, the low refraction layer being incontact with the inner surface of the substrate inside whichilluminating light propagates and being lower in refractive index thanthe substrate is provided, thereby ensuring a sufficient amount of guidelight propagating inside the substrate, reducing non-uniformity indisplay illumination, further reducing in thickness and weight of adisplay apparatus mounting these thereon to enable a high qualitydisplay.

EIGHTH EMBODIMENT

A structure of a liquid crystal displaying device according to thepresent embodiment is illustrated in FIG. 15. The structure of theliquid crystal dispalying device shown in FIG. 15 is different from thestructure described in reference to FIG. 5 in the above seventhembodiment in a point described below. According to the structure shownin FIG. 5, a seal agent 20 is positioned at an outer peripheral portionof a liquid crystal 19 in a liquid crystal layer 8 and sandwiched inadjacent spaces of a first and a second directing layers 18 a and 18 bof the liquid crystal layer 8. And a light blocking layer 502 isarranged so as to be adjusted with, namely overlap, the seal agent 20.Correspondingly, according to the structure shown in FIG. 15 in thepresent embodiment, the seal agent 20 exists not only at the outerperiphery portion of the liquid crystal 19 in the liquid crystal layer8, but also at the outer periphery portion of the first directing layer18 a, a transparent electrode layer 7, a phase difference layer 6, apolarizing layer 5, and a color filter layer 4, instead of not providingwith the light blocking layer 502. In other words, the first directinglayer 18 a, a transparent electrode layer 7, a phase difference layer 6,a polarizing layer 5, and a color filter layer 4 do not exist on theseal agent 20. Thus, striping off in each layer forming a multilayerstructure is restrained and reliability may be improved.

The above structure according to the present embodiment was prepared byapplying selectively material of each layer through a printing methodwhile avoiding a region applied with the seal agent 20 when forming thefirst directing layer 18 a, a transparent electrode layer 7, a phasedifference layer 6, a polarizing layer 5, and a color filter layer 4.

As described above, according to the present embodiment same as the isabove embodiment, in the optical modulating display device, specificallythe liquid crystal displaying device, the low refraction layer being incontact with the inner surface of the substrate inside whichilluminating light propagates and being lower in refractive index thanthe substrate is provided, thereby ensuring a sufficient amount of guidelight propagating inside the substrate, reducing non-uniformity indisplay illumination, further reducing in thickness and weight of adisplay apparatus mounting these thereon to enable a high qualitydisplay.

NINTH EMBODIMENT

FIGS. 16A to 16D are views showing production processes of a liquidcrystal displaying device according to ninth embodiment of the presentinvention. Constituents same as the third embodiment are shown in thesame symbols. Difference between the third embodiment and the presentninth embodiment is in a point that both are different in a productionmethod for protruded portion 11.

As shown in FIG. 16A, a liquid crystal displaying portion 14 prepared inthe third embodiment was arranged so that a first glass substrate 1 a ispositioned in a upper position in the figure. UV curing transparentresin is applied on the liquid crystal displaying portion 14 to form atransparent resin layer 49.

As shown in FIG. 16B, a protruded shape of which a cross-sectional shapewas almost V-shape was scattered in dotted form within a displayingsurface, or a metal mold 15 formed in a linear form was arranged in anupper position of the transparent resin layer 49, and pressure 17 wasapplied from above to print the protruded shape of the metal mold 15 onthe transparent resin layer 49.

As shown in FIG. 16C, while applying pressure from above, ultravioletlight 50 is introduced from first side end of a first substrate 1 a ofthe liquid crystal displaying portion 14 into the first substrate 1 a topolymerize and harden up the UV curing resin.

As shown in FIG. 16D, the metal mold 15 was striped off from thetransparent resin layer 49 formed on the liquid crystal displayingportion 14. Thereby, the protruded shape of the metal mold 15 wasprinted on the transparent resin layer 49 and the first glass substratela and the transparent resin layer 49 was in optically close contactwith each other. Thereby, the protruded portion 11 is formed on thefirst glass substrate 1 a and then the displaying device in the presentembodiment is completed.

As described above, according to the present embodiment same as theabove embodiment, in the optical modulating display device, specificallythe liquid crystal displaying device, the low refraction layer being incontact with the inner surface of the substrate inside whichilluminating light propagates and being lower in refractive index thanthe substrate is provided, thereby ensuring a sufficient amount of guidelight propagating inside the substrate, reducing non-uniformity indisplay illumination, further reducing in thickness and weight of adisplay apparatus mounting these thereon to enable a high qualitydisplay.

TENTH EMBODIMENT

FIGS. 17A and 17B are views illustrating a production process for aliquid crystal displaying device according to tenth embodiment of thepresent invention. Constituents same as the third embodiment are shownin the same symbols. Difference between the third embodiment and thepresent tenth embodiment is in a point of a production method for aprotruded portion 11.

As shown in FIG. 17A, a liquid crystal displaying portion 14 prepared inthe third embodiment was arranged so that a first glass substrate 1 a isin an upper position in the figure. UV curing resin being almost thesame in refractive index as the first transparent substrate, or UVcuring transparent resin being almost the same in refractive index as atransparent resin sheet, is applied on the first transparent substrateto form a transparent resin layer 49.

A protruded shape of which a cross-sectional shape was almost V-shapewas scattered in dotted form within a displaying surface on thetransparent resin layer 49 or the transparent resin sheet 16 formed in alinear form was attached thereon.

As shown in FIG. 17B, ultraviolet ray 50 is illuminated from above theliquid crystal displaying portion 14, and a UV curing resin forming thetransparent resin layer 49 is polymerized and hardened, thereby thefirst transparent substrate la and the transparent resin sheet 16 arebrought into optically close contact with each other. Thus, theprotruded portion 11 is formed on the first glass substrate 1 a tocomplete the liquid crystal displaying device in the present embodiment.

As described above, according to the present embodiment same as theabove embodiment, in the optical modulating display device, specificallythe liquid crystal displaying device, the low refraction layer being incontact with the inner surface of the substrate inside whichilluminating light propagates and being lower in refractive index thanthe substrate is provided, thereby ensuring a sufficient amount of guidelight propagating inside the substrate, reducing non-uniformity indisplay illumination, further reducing in thickness and weight of adisplay apparatus mounting these thereon to enable a high qualitydisplay.

ELEVENTH EMBODIMENT

In eleventh embodiment of the present invention, a liquid crystaldisplaying device prepared in the above embodiment is divided into twoor more displaying devices to simultaneously prepare at least two ormore liquid crystal displaying devices. Namely, after assembling adisplaying portion 14, a protruded portion 11 is formed, thereafter theliquid crystal displaying device is divided into a plurality ofindividual displaying devices to simultaneously prepare at least two ormore liquid crystal displaying devices. Thereby, reliability of processis improved and yield ratio is enhanced. Moreover, two or more liquidcrystal displaying devices are simultaneously formed to enableproduction cost to be reduced.

As described above, according to the present embodiment same as theabove embodiment, in the optical modulating display device, specificallythe liquid crystal displaying device, the low refraction layer being incontact with the inner surface of the substrate inside whichilluminating light propagates and being lower in refractive index thanthe substrate is provided, thereby ensuring a sufficient amount of guidelight propagating inside the substrate, reducing non-uniformity indisplay illumination, further reducing in thickness and weight of adisplay apparatus mounting these thereon to enable a high qualitydisplay.

TWELFTH EMBODIMENT

According to twelfth embodiment in the present invention, beforeassembling a pair of first and second substrates, a score is previouslyprovided on one or both inner surfaces of the first and secondsubstrates or a surface facing in a direction in which an opticalmodulating layer or liquid crystal layer exist when assembling the firstand second substrates. After forming protrusions and grooves on thesurface of an observer's side of a protruded portion 11, a displayingdevice is divided into a plurality of individual displaying devices.Specifically, after forming a multilayer structure on each substratethrough a method described in the above embodiment, a score ispreviously provided to fit a cutting section which finally dividing thedisplaying device into a plurality of individual displaying devices.Thereafter, assembly of the displaying portion is performed and furtherthe protruded portion 11 is formed to simultaneously prepare at leasttwo or more displaying devices by cutting the displaying device alongthe score. Thereby, yield ratio in process of division may be improved.

As described above, according to the present embodiment same as theabove embodiment, in the optical modulating display device, specificallythe liquid crystal displaying device, the low refraction layer being incontact with the inner surface of the substrate inside whichilluminating light propagates and being lower in refractive index thanthe substrate is provided, thereby ensuring a sufficient amount of guidelight propagating inside the substrate, reducing non-uniformity indisplay illumination, further reducing in thickness and weight of adisplay apparatus mounting these thereon to enable a high qualitydisplay.

THIRTEENTH EMBODIMENT

FIG. 18 is a front view showing a cellular phone as a display apparatusaccording to thirteenth embodiment in the present invention. In thepresent embodiment, the cellular phone is provided with it in acondition in which the displaying region of an optical modulatingdisplay device according to the above embodiment is observable. Forinstance, as shown in FIG. 18, the cellular phone includes a main body601, an antenna 602, an operational region 603, and a displaying portion500. According to the present invention, a displaying device can bereduced in thickness and weight and a high quality display is enabled.

In the present embodiment, the cellular phone is shown as the displayapparatus, however the display apparatus is not limited to the cellularphone.

In addition, the present invention is not limited to the eachembodiment, and it is obvious that each embodiment may be suitablymodified within a scope of technical thought of the present invention.

Industrial Applicability

As described above, a low refraction layer being in contact with aninner surface of a substrate inside which illuminating light propagatesand being lower in refractive index than the substrate is provided in anoptical modulating display device, specifically a liquid crystaldisplaying device, thereby achieving the optical modulating displaydevice provided with an improved flat type illuminating device. Thisenables a sufficient amount of guide light propagating inside thesubstrate to be ensured and non-uniformity in display illumination to bereduced, further enables a display apparatus mounting these thereon tobe reduced in thickness and weight and a high quality display to beachieved.

1. An optical modulating display device including a multilayer structurecontaining an optical modulating layer and a pair of first and secondsubstrates sandwiching the multilayer structure: wherein at least thefirst substrate is constituted so that light propagates therein; themultilayer structure is constituted so that a boundary surface betweenthe first substrate and a low refraction layer causes total reflectionof light entering into the boundary surface in an oblique direction byincluding the low refraction layer being lower in refractive index thanthe first substrate and being in direct contact with the firstsubstrate; and the optical modulating layer comprises a liquid crystallayer and the multilayer structure further includes a polarizing layertransmitting a specific polarized light between the low refraction layerand the liquid crystal layer.
 2. An optical modulating display device asclaimed in claim 1, wherein a refractive index (nL) of the lowrefraction layer and a refractive index (nl) of the first substrate meeta condition given by nL−nl<−0.01.
 3. (canceled)
 4. An optical modulatingdisplay device as claimed in claim 1, further including a reflectionstructure for reflecting at a right angle, or nearly right angle, to theboundary surface at least a part of the light entering in an obliquedirection from the first substrate at an opposite side to the lowrefraction layer with reference to the first substrate.
 5. An opticalmodulating display device as claimed in claim 1, wherein the reflectionstructure comprises a layered structure having at least either of aplurality of protrusions and a plurality of grooves at an opposite sideto the first substrate.
 6. An optical modulating display device asclaimed in claim 5, wherein at least either of the plurality ofprotrusions and the plurality of grooves exist in almost the same regionas a displaying region of the optical modulating display device.
 7. Anoptical modulating display device as claimed in claim 1, wherein the lowrefraction layer comprises a transparent material.
 8. An opticalmodulating display device as claimed in claim 1, wherein the lowrefraction layer comprises SiO₂.
 9. An optical modulating display deviceas claimed in claim 1, wherein the low refraction layer comprises MgF.10. (canceled)
 11. An optical modulating display device as claimed inclaim 1, wherein the polarizing layer positioned between the lowrefraction layer and the liquid crystal layer comprises a plurality ofcolor polarizing layers transmitting only specific polarized light ofdifferent specific wavelength band and being spatially arranged withineach pixel region.
 12. An optical modulating display device as claimedin claim 1, wherein at least one or more phase difference layer inaddition to the polarizing layer are positioned between the lowrefraction layer and the liquid crystal layer.
 13. An optical modulatingdisplay device as claimed in claim 1, wherein the polarizing layercomprises a plurality of color polarizing layers transmitting onlyspecific polarized light of different specific wavelength band and beingspatially arranged within each pixel region and the plurality of colorpolarizing layers and at least one or more phase difference layer arepositioned between the low refraction layer and the liquid crystallayer.
 14. An optical modulating display device as claimed in claim 1,wherein the multilayer structure includes a laminated body laminatedwith a color filter layer transmitting light of different specificwavelength band, the polarizing layer, and at least one or more phasedifference layer in this order between the low refraction layer and theliquid crystal layer.
 15. An optical modulating display device asclaimed in claim 1, wherein a light source is arranged in the vicinityof first side end of the first substrate and the first side end isprotruded outside compared with a side end of a second substrate.
 16. Anoptical modulating display device as claimed in claim 1, wherein themultilayer structure further includes a seal member provided forattaching the pair of first and second substrates in a peripheral regionof the liquid crystal layer included in the multilayer structure, and alight blocking layer adjusted so as to overlap with the seal memberviewed from a direction perpendicular to the boundary surface.
 17. Anoptical modulating display device as claimed in claim 1, wherein themultilayer structure further includes a seal member provided forattaching the pair of first and second substrates in a peripheral regionof a laminated body laminated with a color filter layer transmittinglight of different specific wavelength band and at least one or morephase difference layer in this order between the low refraction layerand the liquid crystal layer.
 18. An optical modulating display deviceas claimed in claim 1, wherein a light source is provided in thevicinity of first side end of the first substrate and a liquid crystalinlet used when injecting a liquid crystal material between the pair offirst and second substrates is provided on a side of the liquid crystallayer different from the first side end.
 19. An optical modulatingdisplay device including a multilayer structure containing an opticalmodulating layer and an optical propagating region having a uniformrefractive index and being constituted so that light propagates therein;wherein the multilayer structure is constituted so that a boundarysurface between the optical propagating region and the low refractionlayer causes total reflection of light entering into the boundarysurface in an oblique direction by including a low refraction layerbeing lower in refractive index than the optical propagating region andbeing in direct contact with the optical propagating region; and theoptical modulating layer comprises a liquid crystal layer and themultilayer structure further includes a polarizing layer transmittingonly specific polarized light between the low refraction layer and theliquid crystal layer.
 20. An optical modulating display device asclaimed in claim 19, wherein a refractive index (nL) of the lowrefraction layer and a refractive index (nl) of the optical propagatingregion meet a condition given by nL−nl<−0.01.
 21. An optical modulatingdisplay device as claimed in claim 19, further including a reflectionstructure for reflecting at a right angle, or nearly right angle, to theboundary surface at least a part of the light entering in an obliquedirection from the optical propagating region at an opposite side to thelow refraction layer with reference to the optical propagating region.22. An optical modulating display device as claimed in claim 19, whereinthe reflection structure comprises a layered structure having at leasteither of a plurality of protrusions or a plurality of grooves at anopposite side to the first substrate.
 23. An optical modulating displaydevice as claimed in claim 19, wherein the low refraction layercomprises a transparent material.
 24. An optical modulating displaydevice as claimed in claim 19, wherein the optical propagating regioncomprises a substrate constituted so that light propagates therein. 25.An optical modulating display device as claimed in claim 19, wherein theoptical propagating region includes a substrate constituted so thatlight propagates therein and a thin film inserted between the substrateand the low refraction layer and being the same in refractive index asthe substrate.
 26. An liquid crystal displaying device including atleast: a first and second substrates forming a pair, wherein at leastfirst substrate is constituted so that light propagates therein; a lightsource provided in the vicinity of a first side end of the firstsubstrate; a multilayer structure sandwiched between the first andsecond substrates, which includes at least an optical modulating layercomprising a liquid crystal layer, a low refraction layer being lower inrefractive index than the first substrate and being in direct contactwith the first substrate, a color filter layer transmitting light ofdifferent specific wavelength band, a polarizing layer positionedbetween the liquid crystal layer and the low refraction layer andtransmitting only specific polarized light, and at least one or morephase difference layer; and a reflection structure for reflecting at aright angle, or nearly right angle, to the boundary surface at least apart of light entering in an oblique direction from the first substrateat an opposite side to the low refraction layer with reference to thefirst substrate: wherein a boundary surface between the first substrateand the low refraction layer causes total reflection of light enteringinto the boundary surface in an oblique direction.
 27. An liquid crystaldisplaying device as claimed in claim 26, wherein a refractive index(nL) of the low refraction layer and a refractive index (nl) of thefirst substrate meet a condition given by nL−nl<−0.01.
 28. A liquidcrystal displaying device as claimed in claim 26, wherein the reflectionstructure comprises a layered structure having at least either of aplurality of protrusions or a plurality of grooves at an opposite sideto the first substrate.
 29. A liquid crystal displaying device asclaimed in claim 28, wherein at least either of a plurality ofprotrusions and a plurality of grooves exist in almost the same regionas a displaying region of the optical modulating display device.
 30. Aliquid crystal displaying device as claimed in claim 26, wherein the lowrefraction layer comprises a transparent material.
 31. A liquid crystaldisplaying device as claimed in claim 26, wherein the low refractionlayer comprises SiO₂.
 32. A liquid crystal displaying device as claimedin claim 26, wherein the low refraction layer comprises MgF.
 33. Aliquid crystal displaying device as claimed in claim 26, wherein thefirst side end of the first substrate is protruded outside compared witha side end of second substrate.
 34. A liquid crystal displaying deviceas claimed in claim 26, wherein the multilayer structure furtherincludes a seal member provided for attaching the pair of first andsecond substrates in a peripheral region of a liquid crystal layerincluded in the multilayer structure and a light blocking layer adjustedso as to overlap with the seal member viewed from a directionperpendicular to the boundary surface.
 35. A liquid crystal displayingdevice as claimed in claim 26, wherein the multilayer structure furtherincludes a seal member provided for attaching the pair of first andsecond substrates in a peripheral region of the color filter layer, thephase difference layer, and the liquid crystal layer.
 36. A liquidcrystal displaying device as claimed in claim 26, wherein a liquidcrystal inlet used when injecting liquid crystal material between thepair of first and second substrates is provided at a side of the liquidcrystal layer different from the first side end.
 37. A liquid crystaldisplaying device including at least: a first and second substratesforming a pair, wherein at least first substrate is constituted so thatlight propagates therein; a light source provided in the vicinity offirst side end of the first substrate; a multilayer structure sandwichedbetween the first and second substrates, which includes at least anoptical modulating layer comprising a liquid crystal layer, a lowrefraction layer being lower in refractive index than the firstsubstrate and further being in direct contact with the first substrate,a plurality of color polarizing layers transmitting only specificpolarized light of different specific wavelength band, being spatiallyarranged within each pixel region and being positioned between the lowrefraction layer and the liquid crystal layer, and at least one or morephase difference layer; and a reflection structure for reflecting at aright angle to, or nearly right angle to, the boundary surface at leasta part of light entering in an oblique direction from the firstsubstrate at an opposite side to the low refraction layer with referenceto the first substrate: wherein a boundary surface between the firstsubstrate and the low refraction layer causes total reflection of lightentering into the boundary surface in an oblique direction.
 38. A liquidcrystal displaying device as claimed in claim 37, wherein a refractiveindex (nL) of the low refraction layer and a refractive index (nl) ofthe first substrate meet a condition given by nL−nl<−0.01.
 39. A liquidcrystal displaying device as claimed in claim 37, wherein the reflectionstructure comprises a layered structure having at least either of aplurality of protrusions and a plurality of grooves at an opposite sideto the first substrate.
 40. A liquid crystal displaying device asclaimed in claim 39, wherein the plurality of protrusions and theplurality of grooves exist in almost the same region as a displayingregion of the optical modulating display device.
 41. A liquid crystaldisplaying device as claimed in claim 37, wherein the low refractionlayer comprises a transparent material.
 42. A liquid crystal displayingdevice as claimed in claim 37, wherein the low refraction layercomprises SiO₂.
 43. A liquid crystal displaying device as claimed inclaim 37, wherein the low refraction layer comprises MgF.
 44. A liquidcrystal displaying device as claimed in claim 37, wherein the first sideend of the first substrate is protruded outside compared with a side endof a second substrate.
 45. A liquid crystal displaying device as claimedin claim 37, wherein the multilayer structure further includes a sealmember provided in a peripheral region included in the multilayerstructure and a light blocking layer adjusted so as to overlap with theseal member viewed from a direction perpendicular to the boundarysurface for attaching the pair of first and second substrates.
 46. Aliquid crystal displaying device as claimed in claim 37, wherein themultilayer structure further includes a seal member provided forattaching the pair of first and second substrates in a peripheral regionof the plurality of color polarizing layers, the phase difference layer,and the liquid crystal layer.
 47. A liquid crystal displaying device asclaimed in claim 37, wherein a liquid crystal inlet used when injectinga liquid crystal material between the pair of first and secondsubstrates is provided at a side of the liquid crystal layer differentfrom the first side end.
 48. An optical modulating display deviceincluding at least: a first and second substrates forming a pair,wherein at least the first substrate is constituted so that lightpropagates therein; a light source provided in the vicinity of firstside end of the first substrate; a multilayer structure sandwichedbetween the first and second substrates, which includes an opticalmodulating layer comprising a liquid crystal layer, a low refractionlayer being lower in refractive index than the first substrate andfurther being in direct contact with the first substrate, a polarizinglayer positioned between the low refraction layer and the liquid crystallayer and transmitting a specific polarized light, and a charged fineparticle filled layer; and a reflection structure for reflecting at aright angle, or nearly right angle, to the boundary surface at least apart of light entering in an oblique direction from the first substrateat an opposite side to the low refraction layer with reference to thefirst substrate: wherein a boundary surface between the first substrateand the low refraction layer causes total reflection of light enteringinto the boundary surface in an oblique direction.
 49. An opticalmodulating display device as claimed in claim 48, wherein a refractiveindex (nL) of the low refraction layer and a refractive index (nl) ofthe first substrate meet a condition given by nL−nl<−0.01.
 50. Anoptical modulating display device as claimed in claim 48, wherein thereflection structure comprises a layered structure having at leasteither of a plurality of protrusions and a plurality of grooves at anopposite side to the first substrate.
 51. An optical modulating displaydevice as claimed in claim 50, wherein at least either of the pluralityof protrusions and the plurality of grooves exist in almost the sameregion as a displaying region of the optical modulating display device.52. An optical modulating display device as claimed in claim 48, whereinthe low refraction layer comprises a transparent material.
 53. Anoptical modulating display device as claimed in claim 48, wherein thelow refraction layer comprises SiO₂.
 54. An optical modulating displaydevice as claimed in claim 48, wherein the low refraction layercomprises MgF.
 55. A production method for an optical modulating displaydevice, comprising the steps of: manufacturing an optical modulatingdevice including a multilayer structure sandwiched between a firstsubstrate constituted so that light propagates therein and a secondsubstrate forming a counterpart to the first substrate, wherein themultilayer structure includes an optical modulating layer comprising aliquid crystal layer, a low refraction layer being in contact with thefirst substrate and comprising a material being lower in refractiveindex than the first substrate, and a polarizing layer positionedbetween the low refraction layer and the liquid crystal layer andtransmitting only specific polarized light; and then, forming areflection structure for reflecting at a right angle, or nearly rightangle, to the boundary surface at least a part of light entering in anoblique direction from the first substrate at an opposite side to thelow refraction layer with reference to the first substrate in theoptical modulating device.
 56. A production method for an opticalmodulating display device as claimed in claim 55, wherein the step offorming the reflection structure further comprises the steps of:applying a UV curing transparent resin on an opposite side to the firstsubstrate; pressing a metal mold having at least either of a pluralityof protrusions and a plurality of grooves on the UV curing transparentresin, while pressing, introducing ultraviolet ray into the firstsubstrate from first side end of the first substrate, and hardening theUV curing transparent resin, thereby printing the shape of the metalmold on the UV curing transparent resin.
 57. A production method of anoptical modulating display device as claimed in claim 55, wherein thestep of forming the reflection structure further comprises the steps of:forming a transparent resin sheet at an opposite side of a firstsubstrate; pressing a metal mold having at least either of a pluralityof protrusions or a plurality of grooves on the transparent resin andapplying pressure thereon, and while applying the pressure thereon,heating the transparent resin sheet up to a temperature of a glasstransition point or higher of the transparent resin sheet, followed byprinting the shape of the metal mold on the transparent resin sheet;while continuing to apply the pressure thereon, cooling down thetransparent resin sheet up to room temperature; and striping off themetal mold from the transparent resin sheet.
 58. A production method ofan optical modulating display device as claimed in claim 55, furthercomprising the steps of: forming the reflection structure; andthereafter, further dividing the optical modulating display device intoa plurality of individual optical modulating display devices.
 59. Aproduction method of an optical modulating display device as claimed inclaim 58, wherein the step of manufacturing the optical modulatingdevice further comprises the steps of assembling the pair of first andsecond substrates and providing previously a score at a side where theoptical modulating layer in at least one of the first and secondsubstrates further exist before the step of assembling.
 60. A productionmethod of a liquid crystal displaying device comprising the steps of:manufacturing a liquid crystal device including a first substrateconstituted so that light propagates therein, a second substrate forminga counterpart to the first substrate, and a multilayer structuresandwiched between the first and second substrates which includes aliquid crystal layer, a low refraction layer being in contact with thefirst substrate and comprising a material being lower in refractiveindex than the first substrate, and a polarizing layer positionedbetween the low refraction layer and the liquid crystal layer andtransmitting only specific polarized light; and thereafter, forming areflection structure for reflecting at a right angle, or nearly rightangle, to the boundary surface at least a part of light entering in anoblique direction from the first substrate at an opposite side to thelow refraction layer with reference to the first substrate in the liquidcrystal device.
 61. A production method of a liquid crystal displayingdevice as claimed in claim 60, wherein the step of forming thereflection structure further comprises the steps of: applying UV curingtransparent resin on an opposite side of the first substrate; andpressing a metal mold having at least either of a plurality ofprotrusions and a plurality of grooves on the UV curing transparentresin, and while pressing, introducing ultraviolet ray from first sideend of the first substrate into the first substrate, followed byhardening the UV curing transparent resin, thereby printing the shape ofthe metal mold on the UV curing transparent resin.
 62. A productionmethod of a liquid crystal displaying device as claimed in claim 60,wherein the step of forming the reflection structure further comprisesthe steps of: forming a transparent resin sheet at an opposite side ofthe first substrate; pressing a metal mold having at least either of aplurality of protrusions or a plurality of grooves on the transparentresin and applying pressure thereon, and while applying the pressurethereon, heating the transparent resin sheet up to a temperature of aglass transition point or higher of the transparent resin sheet,followed by printing the shape of the metal mold on the transparentresin sheet; while continuing to apply the pressure thereon, coolingdown the transparent resin sheet up to room temperature; and stripingoff the metal mold from the transparent resin sheet.
 63. A productionmethod of a liquid crystal displaying device as claimed in claim 60,further including a step of dividing the liquid crystal displayingdevice into a plurality of individual liquid crystal displaying devicesafter a step of forming the reflection structure.
 64. A productionmethod of a liquid crystal displaying device as claimed in claim 63,wherein the step of manufacturing the liquid crystal device furtherincludes a step of assembling the pair of first and second substrates,and a step of previously providing a score at a side in which the liquidcrystal layer exists in at least one of the first and second substrates.